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A 7-year-old boy was exposed to his sibling who is suffering from impetigo, a highly infectious disease caused by gram posities bacteria. The child has small multiple pustules on his face which erupted and these are accompanied by high-grade fever. The fever in this case is probably triggered by the release of: A. Lipoxins C. Thromboxanes B. Protectins D. Prostaglandins 10. A 35-year-old woman underwent a Cesarean Section with no complications. On day 3 after the operation, what is the expected histologic finding on the surgical wound site? A. Neutrophils are seen at the incision margin, migrating toward the fibrin clot B. Neovascularization reaches its peak; the new vessels are leaky, allowing the passage of plasma proteins and fluid into the extravascular tissue C. Neutrophils are largely been replaced by macrophages and granulation tissue progressively invades the incision site D. Fibroblasts progressively migrate into the granulation tissue 11. The initial mechanism in the formation of transudates is: A. Increased vascular permeability B. Decreased plasma oncotic pressure C. Increased interstitial osmotic pressure D. Increased hydrostatic pressure 12. Which of the following is a sign of septic shock? A. Tachypnea B. Tachycardia C. Cool, clammy skin D. Vasodilation

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fever mediators prostaglandins pyrogens gram positive bacteria infection

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wound healing histologic findings day 3 surgical incision neutrophils macrophages granulation tissue

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transudate formation hydrostatic pressure oncotic pressure mechanism edema

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septic shock clinical features vasodilation warm skin signs

GradeResponse

Here are the answers based on Robbins Textbook of Pathology (supplemented where needed from core pathology principles covered in Robbins):

Question 9 — Answer: D. Prostaglandins

Robbins explains that fever is triggered by endogenous pyrogens (IL-1, IL-6, TNF) released in response to microbial products (e.g., gram-positive bacterial toxins like those in impetigo caused by Staphylococcus aureus or Streptococcus pyogenes). These cytokines act on the hypothalamus to induce the production of prostaglandins — specifically PGE₂ — via the cyclooxygenase (COX) pathway. PGE₂ raises the hypothalamic set point, producing fever.

Lipoxins and protectins are anti-inflammatory mediators (they resolve inflammation, not promote fever).
Thromboxanes are involved in platelet aggregation and vasoconstriction, not fever.

Robbins Basic Pathology — Chapter on Inflammation: Prostaglandins derived from arachidonic acid via the COX pathway are the principal mediators of fever, pain, and vasodilation.

Question 10 — Answer: C. Neutrophils are largely replaced by macrophages and granulation tissue progressively invades the incision site

Robbins describes the timeline of wound healing by primary intention as follows:

Time	Histologic Finding
Within 24 hrs	Neutrophils appear at incision margins, migrating toward fibrin clot
24–48 hrs	Epithelial cells migrate and proliferate
Day 3	Neutrophils replaced by macrophages; granulation tissue begins to invade
Day 5	Granulation tissue fills incision; neovascularization peaks; collagen fibrils appear
Week 2+	Fibroblasts proliferate; collagen accumulates; leukocytes and edema disappear

Option A describes Day 1.
Option B (peak neovascularization) describes Day 5.
Option D (fibroblast migration into granulation tissue) describes end of first week.

Robbins Basic Pathology — Chapter on Tissue Renewal, Repair, and Regeneration.

Question 11 — Answer: D. Increased hydrostatic pressure

Robbins distinguishes transudates from exudates based on the Starling forces:

A transudate is a protein-poor, low-specific-gravity fluid caused by a hemodynamic imbalance — the primary mechanism is increased hydrostatic pressure (e.g., in heart failure, portal hypertension) forcing fluid out of vessels.
Decreased plasma oncotic pressure (e.g., hypoalbuminemia) can also cause transudates but is a secondary mechanism.
Increased vascular permeability and increased interstitial osmotic pressure produce exudates, not transudates.

The initial and most direct mechanism = increased hydrostatic pressure.

Robbins Basic Pathology — Chapter on Hemodynamic Disorders: Transudates form when hydrostatic pressure exceeds oncotic pressure, most commonly from elevated venous pressure.

Question 12 — Answer: D. Vasodilation

Robbins characterizes septic shock as distinct from other forms of shock precisely because of its hyperdynamic/vasodilatory (warm) phase:

Feature	Septic Shock	Hypovolemic/Cardiogenic Shock
Skin	Warm, flushed (early)	Cool, clammy
Vascular tone	Vasodilation	Vasoconstriction
Cardiac output	High (early)	Low

Tachycardia and tachypnea occur in ALL types of shock and are non-specific.
Cool, clammy skin (Option C) is the hallmark of hypovolemic or cardiogenic shock, NOT septic shock.
Vasodilation is the pathognomonic feature of septic shock, caused by massive release of cytokines (TNF, IL-1) leading to NO-mediated vasodilation.

Robbins Basic Pathology — Chapter on Hemodynamic Disorders, Shock: Septic shock is characterized by peripheral vasodilation and maldistribution of blood flow due to systemic inflammatory mediators.

13. A 50-year-old male with a history of long-standing hypertension and non-compliance to medication is brought into the ER due to difficulty of breathing. Chest X-ray findings revealed pulmonary edema of both lung bases and left ventricular hypertrophy. The edema of this case is due to: A. Increased hydrostatic pressure B. Decreased plasma oncotic pressure C. Inflammatory cause D. Microvascular injury 14. A 55-year-old woman has had discomfort and swelling of the left leg for the past week. On physical examination, the leg is slightly difficult to move, but on palpation, there is no pain. A venogram shows thrombosis of deep left leg veins. Which of the following mechanisms is most likely to cause this condition? A. Stasis of blood B. Loss of venous valves C. Weakening of leg muscles D. Endothelial proliferation 15. All of the following hemodynamic events are correctly matched with the associated condition EXCEPT: A. right atrial thrombosis - cerebral infarct B. venous thrombosis - pulmonary infarct C. fat embolism - Caisson disease D. gas embolism - status post surgery 16. A 37-year-old seafarer recently complained of increasing lethargy for a week and easy bruising. He has been out to sea for almost a year because his employer requested his services. On physical examination, his gums are slightly inflamed and bleeding and there are cutaneous petechial hemorrhages particularly in the area of the cheek. Which among the following is TRUE A. His extended stay in the sea has significantly reduced his vitamin K levels B. An autosomal dominant disorder of collagen is expected in this condition C. His vitamin C levels have significantly decreased due to his diet D. None of the above 17. Which of the following statements is correct about Niemann-Pick disease? A. Enzyme defect is a deficiency of sphingomyelinase B. Enzyme defect is a deficiency of glucocerebrosidase C. Enzyme defect is a deficiency of hexosaminidase A D. Enzyme defect is a deficiency of glucose-6-phosphatase E. Enzyme defect is a deficiency of lysosomal glucosidase (acid maltase) 18. The clinical findings of Edward syndrome? A. Abnormally small mouth and jaw, low set ears, clenched hands, overlapping of the fingers, and rocker-bottom feet B. Cleft lip and palate, malformed ears, cardiac defects, wide set nipples, webbed neck and polydactyly C. Mental retardation, high pitched cat-like cry, congenital heart disease, and microcephaly D. Testicular atrophy, female distribution of hair, gynecomastia, and infertility

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pulmonary edema hypertension left ventricular hypertrophy increased hydrostatic pressure transudate

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deep vein thrombosis Virchow's triad stasis hypercoagulability endothelial injury pathogenesis

GradeResponse

Based on Robbins Textbook of Pathology (core content), here are the answers:

Question 13 — Answer: A. Increased hydrostatic pressure

This patient has long-standing hypertension → left ventricular hypertrophy → diastolic/systolic dysfunction → elevated left-sided filling pressures → increased pulmonary capillary hydrostatic pressure → pulmonary edema (transudate).

Robbins explains that in cardiac failure, the rise in venous and capillary hydrostatic pressure overwhelms the oncotic pressure holding fluid in vessels, forcing a protein-poor transudate into the interstitium and alveoli. This is the classic mechanism of cardiogenic pulmonary edema.

Option B (decreased oncotic pressure) is seen in hypoalbuminemia (nephrotic syndrome, liver failure) — no such history here.
Options C & D (inflammatory/microvascular injury) produce exudates, not this clinical picture.

Robbins Basic Pathology — Hemodynamic Disorders: Heart failure raises hydrostatic pressure in pulmonary capillaries, resulting in bilateral pulmonary edema.

Question 14 — Answer: A. Stasis of blood

This is a classic presentation of deep vein thrombosis (DVT) — painless swelling (Phlegmasia alba dolens or silent DVT). Robbins attributes venous thrombosis to Virchow's Triad:

Stasis of blood flow
Endothelial injury
Hypercoagulability

In the deep leg veins specifically, stasis is the predominant initiating factor — sluggish flow allows clotting factors and platelets to accumulate without being washed away. This patient has no stated history of trauma (ruling out endothelial injury) or hypercoagulable disorder, making stasis the most likely culprit.

Loss of venous valves is a consequence of DVT, not a cause.
Endothelial proliferation is not a thrombotic mechanism.

Robbins Basic Pathology — Hemodynamic Disorders, Thrombosis: Stasis is the major predisposing factor in deep venous thrombosis of the lower extremities.

Question 15 — Answer: C. Fat embolism — Caisson disease

The question asks for the incorrect match:

Pairing	Correct?
A. Right atrial thrombosis → cerebral infarct	✅ Paradoxical embolism via PFO, or thromboembolism to cerebral vessels
B. Venous thrombosis → pulmonary infarct	✅ DVT → pulmonary embolism → infarct
C. Fat embolism → Caisson disease	❌ WRONG — Caisson disease is caused by gas (nitrogen) embolism (decompression sickness), NOT fat embolism
D. Gas embolism → post-surgery	✅ Iatrogenic air embolism can occur post-operatively

Caisson disease (decompression sickness) results from rapid ascent causing dissolved nitrogen to form gas bubbles in tissues and blood — this is gas embolism. Fat embolism is associated with long bone fractures and liposuction.

Robbins Basic Pathology — Embolism: Caisson disease is a form of gas embolism caused by nitrogen bubble formation during decompression.

Question 16 — Answer: C. His vitamin C levels have significantly decreased due to his diet

This is scurvy (Vitamin C deficiency). The clinical clues are:

Seafarer with a restricted diet (no fresh fruits/vegetables) for nearly a year
Bleeding gums (perifollicular/gingival hemorrhages)
Petechial hemorrhages in the skin

Robbins explains that Vitamin C (ascorbic acid) is essential for the hydroxylation of proline and lysine in collagen synthesis. Deficiency leads to defective collagen → weakness of vessel walls → hemorrhagic manifestations.

Option A (Vitamin K deficiency) would cause coagulopathy (elevated PT/INR), not gum bleeding + petechiae in this pattern.
Option B (autosomal dominant collagen disorder) refers to conditions like Ehlers-Danlos syndrome — there is no genetic basis here; this is dietary/acquired.

Robbins Basic Pathology — Environmental and Nutritional Diseases: Scurvy results from Vitamin C deficiency, impairing collagen synthesis and causing perifollicular hemorrhages, bleeding gums, and poor wound healing.

Question 17 — Answer: A. Enzyme defect is a deficiency of sphingomyelinase

Robbins clearly distinguishes the lysosomal storage diseases:

Disease	Enzyme Deficiency
Niemann-Pick disease	Sphingomyelinase → accumulation of sphingomyelin
Gaucher disease	Glucocerebrosidase (Option B)
Tay-Sachs disease	Hexosaminidase A (Option C)
Von Gierke disease	Glucose-6-phosphatase (Option D)
Pompe disease	Lysosomal glucosidase/acid maltase (Option E)

Robbins Basic Pathology — Genetic Disorders: Niemann-Pick disease is caused by sphingomyelinase deficiency, leading to sphingomyelin accumulation in phagocytic cells and neurons.

Question 18 — Answer: A. Abnormally small mouth and jaw, low-set ears, clenched hands with overlapping fingers, and rocker-bottom feet

Edwards syndrome = Trisomy 18. Robbins lists its features as:

Small mouth and micrognathia (small jaw)
Low-set, malformed ears
Clenched fists with overlapping fingers (index over 3rd, 5th over 4th) — pathognomonic
Rocker-bottom feet
Congenital heart defects
Severe intellectual disability

The other options correspond to:

B → Trisomy 13 (Patau syndrome): cleft lip/palate, polydactyly, cardiac defects
C → Cri-du-chat syndrome (5p deletion): cat-like cry, microcephaly, intellectual disability
D → Klinefelter syndrome (47,XXY): testicular atrophy, gynecomastia, infertility

Robbins Basic Pathology — Genetic Disorders: Trisomy 18 (Edwards syndrome) is characterized by overlapping fingers, rocker-bottom feet, micrognathia, and low-set ears; most affected infants die within the first year of life.

9. A stillborn fetus is found to have polydactyly, an umbilical hernia, and cleft lip and palate. Autopsy showed a ventral septal defect, renal dysplasia, and holoprosencephaly. Karyotyping will likely show A. Trisomy 21 B. Trisomy 22 C. Trisomy 13 D. Trisomy 18 20. A 14-year-old female patient presents with clinical features of failure to develop secondary sex characteristics, short stature, primary amenorrhea, infertility, cystic hygroma, and webbed neck. What is the diagnosis? A. Klinefelter syndrome C. Patau syndrome B. Edward syndrome D. Turner syndrome 21. TRUE statement/s about Wiskott-Aldrich syndrome: A. Symptom triad of eczema, thrombocytopenia, and sinopulmonary infections B. X-linked recessive disorder C. Progressive deletion of B and T cells D. All are correct statements 22. Which of the following is produced by human cells in response to viral infection? A. Tumor necrosis factor C. Interleukin-2 B. Interferon D. Interleukin-5 23. A 65-year-old male complained of hematuria. He was diagnosed with arthritis many years ago. On physical examination, ulnar deviation and swan-neck deformities of his fingers were both noted. Previous laboratory studies showed markedly elevated rheumatoid factor and cyclic citrullinated peptide serologic titers. On ultrasonography, there was a mass lesion seen at the intravesical area. Endoscopic biopsy of the lesion revealed a marked deposition of pink amorphous material. Congo red staining was performed which showed an apple-green birefringence under polarized light. Which of the following precursor proteins most likely gave rise to the mass lesion? A. Serum amyloid-associated protein C. Amyloid precursor protein B. Lambda immunoglobulin light chains D. Beta-2-microglobulin 24. A 38-year-old man has chronic cough with fever that have persisted for six months. The chest radiograph reveals a diffuse reticulonodular pattern. Microscopically on transbronchial biopsy, there are areas of inflammation containing central necrosis, epithelioid macrophages, Langhan's giant cells, and lymphocytes. These findings are most typically seen for which of the following hypersensitivity types? A. Type I B. Type I! C. Type III D. Type IV 25. A malignant tumor is said to be poorly differentiated in morphology if it has which of the following? A. A very high nucleo-cytoplasmic ratio C. Extensive necrosis B. Poor resemblance to the cell of origin D. Loss of the normal function of cells 26. The M in TNM staging stands for? A. Mortality C. Metastasis to local sites B. Morbidity D. Metastasis to distant sites 27. A 10-year-old boy presented with abdominal distention. An abdominal CT scan shows bowel obstruction at the level of the ileocecal area measuring 7.0 cm. Bowel resection was performed and a colostomy was done. On histopathologic examination, the mass is composed of round blue cells with moderate to scanty cytoplasm having a starry-sky pattern. It was signed out as Burkitt's lymphoma by the pathologist on duty. Which of the following best describes the origin of this condition? A. Deletion in chromosomes 8 and 14 D. Frameshift mutation in chromosomes 8 and 14 C. Translocation between 8 and 14 D. Trinucleotide mutation in chromosomes 8 and 14 28. A study is performed to analyze characteristics of

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Trisomy 13 Patau syndrome polydactyly holoprosencephaly cleft lip palate renal dysplasia cardiac defects

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Turner syndrome monosomy X features amenorrhea webbed neck short stature cystic hygroma infertility

GradeResponse

Here are all the answers based on Robbins Textbook of Pathology:

Question 19 — Answer: C. Trisomy 13 (Patau Syndrome)

The constellation of findings — polydactyly, cleft lip and palate, holoprosencephaly, ventricular septal defect, renal dysplasia, and umbilical hernia — is the classic presentation of Trisomy 13 (Patau syndrome).

Robbins lists the hallmark features:

Feature	Trisomy 13
CNS	Holoprosencephaly (failure of forebrain division)
Face	Cleft lip and palate, cyclopia, microphthalmia
Limbs	Polydactyly
Cardiac	VSD, ASD
Renal	Renal dysplasia/cystic kidneys
Abdominal wall	Umbilical hernia/omphalocele

Trisomy 21 (Down syndrome): intellectual disability, flat facies, epicanthal folds, Brushfield spots — no holoprosencephaly
Trisomy 18 (Edwards): overlapping fingers, rocker-bottom feet — no polydactyly or holoprosencephaly
Trisomy 22: rare, not classically associated with this pattern

Robbins Basic Pathology — Genetic Disorders: Trisomy 13 is characterized by midline defects including holoprosencephaly, cleft lip/palate, polydactyly, and cardiac/renal anomalies; most affected infants are stillborn or die within the first year.

Question 20 — Answer: D. Turner Syndrome

A 14-year-old female with no secondary sex characteristics, short stature, primary amenorrhea, infertility, webbed neck, and cystic hygroma is the textbook description of Turner syndrome (45,X).

Robbins key features:

Karyotype: 45,X (monosomy X)
Gonadal dysgenesis → streak gonads → hypergonadotropic hypogonadism → no puberty, primary amenorrhea, infertility
Short stature, webbed neck (pterygium colli)
Cystic hygroma (lymphedema in utero)
Bicuspid aortic valve / coarctation of the aorta
Klinefelter (47,XXY): affects males
Patau / Edwards: associated with severe structural defects and early death, not isolated pubertal failure

Robbins Basic Pathology — Genetic Disorders: Turner syndrome results from complete or partial monosomy X; affected females show short stature, gonadal dysgenesis, webbed neck, and lymphedema.

Question 21 — Answer: D. All are correct statements

Robbins describes Wiskott-Aldrich syndrome (WAS) as:

X-linked recessive immunodeficiency (mutation in WASP gene on X chromosome) ✅
Classic triad: eczema + thrombocytopenia + recurrent sinopulmonary infections ✅
Progressive depletion of both B and T lymphocytes over time, leading to combined immunodeficiency ✅

All three statements are correct, making D the answer.

Robbins Basic Pathology — Diseases of the Immune System: WAS is an X-linked disorder characterized by the triad of eczema, thrombocytopenia, and immunodeficiency with progressive loss of B and T cells.

Question 22 — Answer: B. Interferon

Robbins explains that human cells infected by viruses produce interferons (IFN-α and IFN-β) as part of the innate antiviral response. Interferons:

Are released by virally infected cells
Signal neighboring cells to upregulate antiviral defenses (via JAK-STAT pathway)
Inhibit viral replication
TNF and IL-2 are produced mainly by immune cells in inflammatory/adaptive responses, not directly as the antiviral response of all human cells
IL-5 is involved in eosinophil activation (allergic/parasitic response)

Robbins Basic Pathology — Innate Immunity: Interferons are produced by virally infected host cells and constitute the primary antiviral cytokine defense.

Question 23 — Answer: A. Serum amyloid-associated (SAA) protein

This patient has long-standing rheumatoid arthritis (ulnar deviation, swan-neck deformity, elevated RF and anti-CCP) → presenting with hematuria and a bladder mass showing Congo red positivity with apple-green birefringence = amyloidosis.

Robbins classifies amyloidosis by precursor protein:

Type	Precursor Protein	Associated Condition
AA amyloidosis	Serum amyloid-associated (SAA) protein	Chronic inflammatory diseases (RA, TB, bronchiectasis)
AL amyloidosis	Immunoglobulin light chains (λ or κ)	Multiple myeloma / plasma cell dyscrasias
Aβ amyloidosis	Amyloid precursor protein	Alzheimer's disease
Aβ₂M amyloidosis	Beta-2-microglobulin	Long-term dialysis

This patient's amyloidosis is reactive/secondary (AA type) from chronic RA. The precursor is SAA protein.

Robbins Basic Pathology — Diseases of the Immune System, Amyloidosis: Reactive systemic (AA) amyloidosis complicates chronic inflammatory conditions such as rheumatoid arthritis; the amyloid is derived from SAA, an acute-phase protein.

Question 24 — Answer: D. Type IV (Delayed-type / Cell-mediated hypersensitivity)

The biopsy shows: central necrosis + epithelioid macrophages + Langhans giant cells + lymphocytes = caseating granuloma = classic morphology of tuberculosis, driven by Type IV hypersensitivity.

Robbins hypersensitivity classification:

Type	Mechanism	Example
I	IgE-mediated	Anaphylaxis, asthma
II	IgG/IgM against cell surface antigens	Hemolytic anemia
III	Immune complex deposition	SLE, post-strep GN
IV	T-cell mediated (CD4 Th1 + macrophage activation)	TB, sarcoidosis, contact dermatitis

Granuloma formation is the hallmark of Type IV hypersensitivity.

Robbins Basic Pathology — Diseases of the Immune System: Type IV hypersensitivity is mediated by sensitized T lymphocytes; granulomatous inflammation with Langhans giant cells is its prototypical morphologic expression.

Question 25 — Answer: B. Poor resemblance to the cell of origin

Robbins defines differentiation in tumors as the degree to which neoplastic cells resemble their normal counterparts morphologically and functionally. A poorly differentiated tumor has:

Poor resemblance to the cell/tissue of origin ✅ (this is the definition)
High nuclear pleomorphism, prominent nucleoli, abnormal mitoses
Option A (high N:C ratio) is a feature of malignancy in general, but is more specifically a feature of anaplasia, not the definition of poor differentiation
Option C (necrosis) occurs in many tumors regardless of differentiation
Option D (loss of function) is a consequence but not the defining morphologic criterion

Robbins Basic Pathology — Neoplasia: Differentiation refers to the extent to which neoplastic cells resemble the corresponding normal parenchymal cells; poorly differentiated tumors bear little resemblance to their cell of origin.

Question 26 — Answer: D. Metastasis to distant sites

In the TNM staging system:

T = Tumor size/local extent
N = regional Node involvement
M = distant Metastasis (M0 = none; M1 = present)

Robbins Basic Pathology — Neoplasia: The M in TNM staging refers to the presence or absence of distant metastases; M1 indicates spread beyond regional lymph nodes to distant organs.

Question 27 — Answer: C. Translocation between chromosomes 8 and 14

Burkitt's lymphoma is characterized histologically by the "starry-sky" pattern (sheets of round blue cells with interspersed tingible-body macrophages). Robbins identifies its molecular hallmark as:

t(8;14)(q24;q32) — translocation of the c-MYC oncogene (chromosome 8) to the immunoglobulin heavy chain locus (chromosome 14), causing constitutive MYC overexpression and uncontrolled B-cell proliferation.

Less common variants: t(2;8) and t(8;22) — also involving MYC with light chain loci
This is a translocation, not a deletion, frameshift, or trinucleotide repeat mutation

Robbins Basic Pathology — Neoplasia / Lymphomas: Burkitt lymphoma invariably carries a translocation involving MYC on chromosome 8, most commonly t(8;14), placing MYC under the control of immunoglobulin gene enhancers.

Question 28 appears to be cut off — please share the complete question and I'll answer it promptly.

A.9. A stillborn fetus is found to have polydactyly, an umbilical hernia, and cleft lip and palate. Autopsy showed a ventral septal defect, renal dysplasia, and holoprosencephaly. Karyotyping will likely show A. Trisomy 21 B. Trisomy 22 C. Trisomy 13 D. Trisomy 18 20. A 14-year-old female patient presents with clinical features of failure to develop secondary sex characteristics, short stature, primary amenorrhea, infertility, cystic hygroma, and webbed neck. What is the diagnosis? A. Klinefelter syndrome C. Patau syndrome B. Edward syndrome D. Turner syndrome 21. TRUE statement/s about Wiskott-Aldrich syndrome: A. Symptom triad of eczema, thrombocytopenia, and sinopulmonary infections B. X-linked recessive disorder C. Progressive deletion of B and T cells D. All are correct statements 22. Which of the following is produced by human cells in response to viral infection? A. Tumor necrosis factor C. Interleukin-2 B. Interferon D. Interleukin-5 23. A 65-year-old male complained of hematuria. He was diagnosed with arthritis many years ago. On physical examination, ulnar deviation and swan-neck deformities of his fingers were both noted. Previous laboratory studies showed markedly elevated rheumatoid factor and cyclic citrullinated peptide serologic titers. On ultrasonography, there was a mass lesion seen at the intravesical area. Endoscopic biopsy of the lesion revealed a marked deposition of pink amorphous material. Congo red staining was performed which showed an apple-green birefringence under polarized light. Which of the following precursor proteins most likely gave rise to the mass lesion? A. Serum amyloid-associated protein C. Amyloid precursor protein B. Lambda immunoglobulin light chains D. Beta-2-microglobulin 24. A 38-year-old man has chronic cough with fever that have persisted for six months. The chest radiograph reveals a diffuse reticulonodular pattern. Microscopically on transbronchial biopsy, there are areas of inflammation containing central necrosis, epithelioid macrophages, Langhan's giant cells, and lymphocytes. These findings are most typically seen for which of the following hypersensitivity types? A. Type l B. Type I! C. Type III D. Type IV 25. A malignant tumor is said to be poorly differentiated in morphology if it has which of the following? A. A very high nucleo-cytoplasmic ratio C. Extensive necrosis B. Poor resemblance to the cell of origin D. Loss of the normal function of cells 26. The M in TNM staging stands for? A. Mortality C. Metastasis to local sites B. Morbidity D. Metastasis to distant sites 27. A 10-year-old boy presented with abdominal distention. An abdominal CT scan shows bowel obstruction at the level of the ileocecal area measuring 7.0 cm. Bowel resection was performed and a colostomy was done. On histopathologic examination, the mass is composed of round blue cells with moderate to scanty cytoplasm having a starry-sky pattern. It was signed out as Burkitt's lymphoma by the pathologist on duty. Which of the following best describes the origin of this condition? A. Deletion in chromosomes 8 and 14 D. Frameshift mutation in chromosomes 8 and 14 C. Translocation between 8 and 14 D. Trinucleotide mutation in chromosomes 8 and 14

Those questions were already answered in my previous response. Here is a clean consolidated summary:

Q19 — C. Trisomy 13 (Patau Syndrome)

Polydactyly + holoprosencephaly + cleft lip/palate + VSD + renal dysplasia + umbilical hernia are the classic midline defects of Trisomy 13.

Q20 — D. Turner Syndrome

45,X — presents with failure of secondary sex development, short stature, primary amenorrhea, infertility, webbed neck, and cystic hygroma (lymphedema in utero).

Q21 — D. All are correct statements

Wiskott-Aldrich syndrome is X-linked recessive, presents with the triad of eczema + thrombocytopenia + sinopulmonary infections, and causes progressive depletion of both B and T cells.

Q22 — B. Interferon

Virally infected human cells produce interferons (IFN-α/β) as the primary innate antiviral response. TNF and interleukins are produced by immune cells in different contexts.

Q23 — A. Serum amyloid-associated (SAA) protein

Long-standing rheumatoid arthritis → reactive (AA) amyloidosis — the precursor is SAA protein, an acute-phase reactant. Congo red with apple-green birefringence confirms amyloid.

Q24 — D. Type IV hypersensitivity

Caseating granulomas (central necrosis + epithelioid macrophages + Langhans giant cells + lymphocytes) are the morphologic hallmark of Type IV (cell-mediated / delayed-type) hypersensitivity, as seen in tuberculosis.

Q25 — B. Poor resemblance to the cell of origin

Differentiation = degree of morphologic resemblance to the normal cell of origin. Poor differentiation = poor resemblance. This is the defining criterion per Robbins.

Q26 — D. Metastasis to distant sites

TNM: T = tumor size, N = regional node involvement, M = distant metastasis (M0 = absent; M1 = present).

Q27 — C. Translocation between chromosomes 8 and 14

Burkitt lymphoma carries t(8;14)(q24;q32) — the c-MYC oncogene (chr 8) is translocated to the immunoglobulin heavy chain locus (chr 14), driving uncontrolled B-cell proliferation. The starry-sky pattern on histology is its morphologic signature.

28. A study is performed to analyze characteristics of malignant neoplasms in biopsy specimens. The biopsies were performed on patients who had palpable mass lesions on digital rectal examination. Of the following microscopic findings, which is most likely to indicate that the neoplasm is malignant? A. Pleomorphism of the nuclei and nucleoli B. Invasion of adjacent structures C. Increased nuclear/cytoplasmic ratio D. Necrosis of the lining epithelium 29. This hepatotrophic virus is the least dangerous because it is self-limited and has no chronic liver disease or carrier state in its natural history. A. Hepatitis A B. Hepatitis B C. Hepatitis C 30. Schistosoma japonicum causes liver cirrhosis by which of the following mechanisms? A. The adult worms obstruct the portal circulation leading to infarction and fibrosis of the liver parenchyma B. The ova produce granuloma formation resulting to fibrosis of the liver parenchyma C. Causes serum alcohol levels to increase to dangerous levels causing steatohepatitis D. Alters iron metabolism and storage causing free radical damage via Fenton reaction

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malignant neoplasm histologic features invasion pleomorphism nuclear cytoplasmic ratio criteria of malignancy

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Schistosoma japonicum liver cirrhosis granuloma ova fibrosis portal hypertension mechanism

GradeResponse

Here are the answers based on Robbins Textbook of Pathology:

Question 28 — Answer: B. Invasion of adjacent structures

While pleomorphism, high N:C ratio, and necrosis are all features associated with malignancy, Robbins is explicit that the single most reliable indicator of malignancy is invasion of adjacent tissues (and metastasis). Cytologic features like pleomorphism and high N:C ratio can be seen in benign reactive conditions (e.g., regenerating epithelium), and necrosis occurs in both benign and malignant lesions.

Robbins states:

"The most reliable feature distinguishing benign from malignant tumors is the presence of invasion — malignant cells breach the basement membrane and invade surrounding stroma, vessels, or adjacent organs."

Pleomorphism (A) and high N:C ratio (C) — features of anaplasia; suggestive but not definitive alone
Necrosis (D) — common in malignancy but not specific
Invasion (B) — definitively malignant behavior; a benign tumor by definition does not invade

Robbins Basic Pathology — Neoplasia: Invasion of adjacent structures is the hallmark of malignancy and the most definitive criterion distinguishing malignant from benign neoplasms.

Question 29 — Answer: A. Hepatitis A

Robbins clearly distinguishes the hepatitis viruses by their clinical behavior:

Virus	Chronicity	Carrier State	Risk of Cirrhosis/HCC
Hepatitis A (HAV)	None — always self-limited	None	None
Hepatitis B (HBV)	Yes (5–10% adults)	Yes	Yes
Hepatitis C (HCV)	Yes (~85%)	Yes	Yes (leading cause of cirrhosis)

Hepatitis A is transmitted fecal-orally, causes acute hepatitis only, is never chronic, has no carrier state, and never leads to cirrhosis or hepatocellular carcinoma. It is therefore the least dangerous of the hepatotropic viruses.

Robbins Basic Pathology — Liver: HAV infection is always self-limited; it does not progress to chronic hepatitis, cirrhosis, or carrier state, making it the most benign of the hepatotropic viruses.

Question 30 — Answer: B. The ova produce granuloma formation resulting in fibrosis of the liver parenchyma

This is a core concept in Robbins. The pathogenesis of hepatic schistosomiasis (caused by S. japonicum, S. mansoni) is:

Adult worms live in the portal/mesenteric veins
They shed eggs (ova) which embolize to the portal triads of the liver
The host mounts a Type IV (cell-mediated) immune response to the ova → granuloma formation
Repeated granuloma formation → periportal fibrosis ("pipe-stem fibrosis" / Symmers' clay-pipe stem fibrosis)
Progressive fibrosis → portal hypertension → varices, splenomegaly, ascites

Option A is incorrect: adult worms do not cause direct infarction
Options C and D describe alcoholic liver disease and hemochromatosis respectively — unrelated to schistosomiasis

Robbins Basic Pathology — Infectious Diseases / Liver: Schistosomal liver disease results from host granulomatous response to trapped ova in portal tracts, leading to periportal (pipe-stem) fibrosis and non-cirrhotic portal hypertension.

32. A 40-year-old male developed fever, headache and nuchal rigidity. CF analysis was done and revealed lymphocytosi slightly decreased sugar and elevated protein. Mucicarmine staining of the CSF showed encapsulated yeast. What is the most likely diagnosis? A. Aspergillosis B. Tuberculosis C. Candidiasis D. Cryptococcosis 33. A 35-year-old woman had experienced dysuria which is accompanied by urinary frequency and flank pain and low-grade fever. Results of the urinalysis showed many WBCs and bacteria, and positive for nitrite. The most likely etiologic agent? A. H. influenzae C. P. vulgaris B. E. coli D. N. gonorrhea 34. A 30-year-old male presents with a reddish chancre on the penile area. The lesion is scraped, and dark field examination is positive for spirochetes. What is the expected histologic finding in this lesion? A. Granulomatous inflammation C. Koilocytosis B. Proliferative endarteritis D. Aggregates of lipid laden macrophages 35. Arsenic is considered as a toxic agent because of its tendency to: A. Irreversibly bind and precipitates hemoglobin B. Cause breakdown of collagen C. Interfere with DNA replication D. Interfere with mitochondrial oxidative phosphorylation 36. Asians are generally more prone to acute alcohol toxicity because of decreased activity of which among the following enzymes? A. Alcohol dehydrogenase B. Aldol dismutase C. Myeloperoxidase D. Alcohol decarboxylase 37. First described in Japan, this disease was discovered when postmenopausal women were found to be chronically poisoned with cadmium from contaminated irrigation water, causing osteoporosis and osteomalacia due to renal disease. A. Itai-Itai C. Minamata B. Hashimoto D. Kikuchi 38. Arsenic trioxide has been historically used to treat what type of malignancy? A. Chronic myelogenous leukemia C. Acute promyelocytic leukemia B. Squamous cell carcinoma D. Basal cell carcinoma 39. Which of the following patients would you expect to manifest marasmus rather than kwashiorkor? A. Four-year-old male with protein-losing enteropathy B. Two-year-old female exclusively fed rice C. Five-year-old male in a drought and famine-stricken community D. Nine-year-old female with nephrotic syndrome

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Cryptococcosis CSF mucicarmine encapsulated yeast lymphocytosis meningitis diagnosis

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marasmus kwashiorkor protein calorie malnutrition difference pathogenesis

GradeResponse

Here are the answers based on Robbins Textbook of Pathology:

Question 32 — Answer: D. Cryptococcosis

The triad of:

Lymphocytic meningitis (lymphocytosis, elevated protein, slightly decreased glucose in CSF)
Mucicarmine-positive encapsulated yeast on CSF staining

is pathognomonic for Cryptococcus neoformans meningitis.

Robbins explains that Cryptococcus has a thick polysaccharide capsule that stains with mucicarmine (red/pink) and India ink (negative staining, showing a halo). It is the most common fungal cause of meningitis, especially in immunocompromised patients (HIV/AIDS).

Aspergillosis: causes hyphae, not encapsulated yeast; rarely causes meningitis
TB meningitis: lymphocytic meningitis but shows NO fungal organisms; acid-fast bacilli instead
Candidiasis: pseudohyphae/budding yeast; mucicarmine negative

Robbins Basic Pathology — Infectious Diseases: Cryptococcal meningitis is characterized by encapsulated yeasts with a gelatinous capsule that stains with mucicarmine; CSF shows lymphocytic pleocytosis with elevated protein and depressed glucose.

Question 33 — Answer: B. Escherichia coli

This is a classic presentation of urinary tract infection / pyelonephritis:

Dysuria, frequency, flank pain, low-grade fever
UA: WBCs, bacteria, positive nitrite (nitrite is produced by gram-negative, nitrate-reducing bacteria)

Robbins identifies E. coli as the causative agent in ~80–85% of community-acquired UTIs. It colonizes the periurethra from the GI tract and ascends to the bladder/kidneys. E. coli is gram-negative and reduces nitrates → nitrite-positive dipstick.

H. influenzae: respiratory pathogen, not a common UTI cause
P. vulgaris: urease-producing; causes struvite stones; less common
N. gonorrhoeae: causes urethritis/STI, not typical ascending UTI; nitrite-negative

Robbins Basic Pathology — Kidney: E. coli is the most common etiologic agent of urinary tract infections; positive urine nitrite reflects gram-negative bacterial metabolism.

Question 34 — Answer: B. Proliferative endarteritis

A painless, indurated reddish chancre on the penis with spirochetes on dark-field microscopy = primary syphilis (Treponema pallidum).

Robbins describes the classic histologic finding of the syphilitic chancre as:

Obliterative/proliferative endarteritis — endothelial proliferation causing narrowing of small vessels
Surrounding dense plasma cell-rich infiltrate (plasma cells are the hallmark inflammatory cell of syphilis)
Perivascular lymphocytic and plasma cell infiltrate
Granulomatous inflammation is seen in tertiary (gummatous) syphilis, not primary
Koilocytosis is the hallmark of HPV infection (condyloma/dysplasia)
Lipid-laden macrophages (foam cells) are seen in lepromatous leprosy or atherosclerosis

Robbins Basic Pathology — Infectious Diseases, Syphilis: The chancre of primary syphilis shows obliterative endarteritis and a dense perivascular infiltrate of plasma cells and lymphocytes.

Question 35 — Answer: D. Interfere with mitochondrial oxidative phosphorylation

Robbins explains that arsenic exerts its toxic effects primarily by:

Binding to sulfhydryl (-SH) groups on enzymes, particularly those involved in the mitochondrial electron transport chain and oxidative phosphorylation
Specifically, arsenite (As³⁺) inhibits pyruvate dehydrogenase and the α-ketoglutarate dehydrogenase complex → disrupts ATP production
Arsenate (As⁵⁺) competes with phosphate in oxidative phosphorylation → uncouples ATP synthesis

This mitochondrial interference leads to cell death, particularly in high-turnover cells (GI epithelium, bone marrow, skin).

Robbins Basic Pathology — Environmental and Nutritional Diseases: Arsenic toxicity results from binding to sulfhydryl groups on enzymes critical to mitochondrial oxidative phosphorylation, leading to cellular energy failure.

Question 36 — Answer: A. Alcohol dehydrogenase

Robbins and pharmacogenomics literature explain that East Asians have a higher prevalence of a variant aldehyde dehydrogenase 2 (ALDH2*2) — however, the question specifically asks about the enzyme causing acute toxicity in the context of decreased activity.

The metabolism of alcohol: Ethanol → (alcohol dehydrogenase) → Acetaldehyde → (aldehyde dehydrogenase) → Acetate

Many Asians have a less active form of aldehyde dehydrogenase (ALDH2), causing acetaldehyde accumulation → flushing, tachycardia, nausea ("Asian flush"). However, among the options given, alcohol dehydrogenase (A) is the only relevant enzyme listed. The other options — aldol dismutase, myeloperoxidase, alcohol decarboxylase — are not involved in ethanol metabolism.

Robbins Basic Pathology — Environmental and Nutritional Diseases: Genetic polymorphisms in alcohol-metabolizing enzymes, particularly decreased aldehyde dehydrogenase activity in East Asians, lead to acetaldehyde accumulation and acute alcohol intolerance.

Question 37 — Answer: A. Itai-Itai

Itai-Itai disease ("it hurts-it hurts" in Japanese) was the first documented mass cadmium poisoning in the world, occurring in the Toyama Prefecture of Japan. Postmenopausal women exposed to cadmium-contaminated rice irrigation water developed:

Renal tubular dysfunction (Fanconi syndrome) → phosphate wasting
Osteomalacia and osteoporosis → severe bone pain and pathologic fractures
Minamata disease: mercury (methylmercury) poisoning → neurological damage
Hashimoto: autoimmune thyroiditis — not an environmental disease
Kikuchi disease: necrotizing lymphadenitis — not cadmium-related

Robbins Basic Pathology — Environmental and Nutritional Diseases: Itai-Itai disease results from chronic cadmium poisoning causing renal tubular damage, phosphaturia, and consequent osteomalacia/osteoporosis.

Question 38 — Answer: C. Acute Promyelocytic Leukemia (APL / AML-M3)

Arsenic trioxide (As₂O₃) is an FDA-approved treatment for Acute Promyelocytic Leukemia (APL), which harbors the t(15;17) translocation producing the PML-RARα fusion protein. Arsenic trioxide works by:

Inducing differentiation and apoptosis of leukemic promyelocytes
Degrading the PML-RARα fusion protein
Used alongside all-trans retinoic acid (ATRA)
CML is treated with imatinib (BCR-ABL inhibitor)
Skin cancers (SCC, BCC) are not treated with arsenic trioxide (though chronic arsenic exposure paradoxically causes skin cancers)

Robbins Basic Pathology — Neoplasia / Leukemias: Arsenic trioxide induces remission in acute promyelocytic leukemia by promoting differentiation and apoptosis of PML-RARα-expressing promyelocytes.

Question 39 — Answer: C. Five-year-old male in a drought and famine-stricken community

Robbins distinguishes the two forms of severe protein-energy malnutrition:

Feature	Marasmus	Kwashiorkor
Cause	Total caloric deficiency (inadequate intake of ALL nutrients)	Protein deficiency with adequate calories
Appearance	Wasted, "skin and bones," no edema	Edematous, "pot belly," skin/hair changes
Serum albumin	Near normal	Markedly decreased
Scenario	Famine, starvation	Weaning onto low-protein diet (e.g., rice/cassava only)

Option C (famine/drought) → total starvation → marasmus ✅
Option A (protein-losing enteropathy) → protein loss → kwashiorkor
Option B (rice-only diet) → adequate calories, deficient protein → kwashiorkor
Option D (nephrotic syndrome) → urinary protein loss → kwashiorkor

Robbins Basic Pathology — Environmental and Nutritional Diseases: Marasmus results from severe deficiency of total calories and all nutrients, as in starvation; kwashiorkor results specifically from protein deficiency in the setting of adequate caloric intake.

Which of the following is CORRECTLY paired? A. Laceration - produced by scrapings B. Abrasion - produced by a blunt object causing jagged edges in the skin C. Puncture - inflicted by a long narrow instrument D. Contusion - inflicted by a sharp object wherein bridging vessels are severed 41. An elevated serum prostatic specific antigen (PSA) together with an elevated alkaline phosphatase level is consistent with which of the following mechanisms? A. Benign prostatic hyperplasia B. Prostatic malignancy C. Cystitis D. Prostatitis 42. A cryptorchid testis would show which of the following features? A. Normal in size or slightly heavier than normal B. Tubules presenting with thickened basement membrane C. The opposite (contralateral) testis is always normal D. The undescended testis has equal risk of malignancy as the normal contralateral testis 43. For the past 5 months, a 30-year-old male noticed a gradual enlargement of his left testis. History revealed he has an undescended testis on the left side but was corrected when he was 2 years old. He underwent orchiectomy and the mass was described as large, cream-white, doughy to firm with a homogenous, lobulated cut surface. Microscopic examination showed sheets of homomorphous population of round cells. The tumor cells are separated into poorly demarcated lobules by a delicate fibrous septae infiltrated by lymphocytes. What is the most likely diagnosis? A. Leydig cell tumor B. Seminoma C. Germinoma D. Dysgerminoma 44. This vulvar lesion presents as papules or macules that eventually coalesce into smooth, white parchment like areas. Microscopically there is epidermal thinning, superficial hyperkeratosis, and dermal fibrosis with a scant mononuclear perivascular infiltrate. A. Lichen simplex chronicus B. Lichen sclerosus C. Vulvar intraepithelial neoplasia D. Conduloma acuminate

Medical Text Search

seminoma testicular tumor histology sheets round cells lymphocytic infiltrate fibrous septa cryptorchid undescended testis

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lichen sclerosus vulvar lesion epidermal thinning hyperkeratosis dermal fibrosis white parchment

GradeResponse

Here are the answers based on Robbins Textbook of Pathology:

Question 40 — Answer: C. Puncture — inflicted by a long narrow instrument

Robbins and forensic pathology define wound types as follows:

Wound Type	Correct Definition
Abrasion	Scraping/rubbing of skin surface — removes superficial epidermis
Laceration	Tearing of skin by blunt force — produces jagged edges with bridging vessels
Contusion	Bruise — blunt trauma causing hemorrhage into tissue without skin breach
Incision	Clean cut by a sharp object
Puncture	Penetrating wound by a long narrow/pointed instrument (e.g., knife, nail)

Evaluating the options:

A — Incorrect: Laceration is from blunt force (tearing), not scraping (that is an abrasion)
B — Incorrect: Abrasion is from scraping/friction, not a blunt object causing jagged edges (that is a laceration)
C — ✅ Correct: Puncture wound is inflicted by a long, narrow pointed instrument
D — Incorrect: Contusion is from blunt trauma with subcutaneous hemorrhage; bridging vessels are severed in lacerations, and sharp objects cause incised wounds, not contusions

Robbins Basic Pathology — Environmental and Nutritional Diseases / Mechanical Injury: Puncture wounds result from penetration by long narrow instruments; lacerations from blunt force tear tissue with bridging vessel strands; abrasions result from surface scraping.

Question 41 — Answer: B. Prostatic malignancy

Robbins explains the significance of PSA and alkaline phosphatase (ALP) together:

Elevated PSA → indicates prostatic pathology (BPH, prostatitis, or carcinoma)
Elevated alkaline phosphatase → specifically suggests osteoblastic bone metastases, which are the hallmark of metastatic prostate adenocarcinoma

Prostate cancer has a predilection for osteoblastic (sclerotic) bone metastases to the axial skeleton, causing markedly elevated ALP (from osteoblast activity).

BPH: can mildly elevate PSA, but does not cause elevated ALP
Prostatitis: can elevate PSA, but does not cause elevated ALP
Cystitis: neither PSA nor ALP is elevated

Robbins Basic Pathology — Male Genital System: Prostate adenocarcinoma metastasizes preferentially to bone (osteoblastic lesions), producing elevated serum PSA and alkaline phosphatase; this combination strongly suggests metastatic disease.

Question 42 — Answer: B. Tubules presenting with thickened basement membrane

Robbins describes the histologic changes seen in cryptorchidism (undescended testis):

Thickening of the basement membrane of seminiferous tubules ✅
Decreased/absent spermatogenesis
Hyalinization of tubules over time
Smaller than normal in size (not larger — ruling out A)
The contralateral (normally descended) testis can also show abnormal spermatogenesis in a proportion of cases — it is NOT always normal (ruling out C)
The undescended testis has a significantly HIGHER risk of malignancy (3–5× greater) than the normally descended testis (ruling out D)

Robbins Basic Pathology — Male Genital System: Cryptorchid testes show tubular atrophy with thickened basement membranes and increased risk of germ cell tumors, including in the contralateral testis in some cases.

Question 43 — Answer: B. Seminoma

The clinical and histologic features are classic for seminoma:

Feature	This Case
History	Corrected undescended (cryptorchid) left testis — major risk factor
Gross	Large, cream-white, doughy to firm, homogeneous lobulated cut surface
Microscopy	Sheets of homomorphous round cells, separated by delicate fibrous septa infiltrated by lymphocytes

This is the textbook description of seminoma per Robbins — the most common testicular germ cell tumor (50% of all testicular tumors).

Leydig cell tumor: contains crystals of Reinke, causes hormonal effects (gynecomastia); does not show this pattern
Germinoma: same histology as seminoma but occurs in the CNS or mediastinum (extragonadal)
Dysgerminoma: histologically identical but occurs in the ovary, not the testis

Robbins Basic Pathology — Male Genital System: Seminoma presents as a homogeneous, cream-white testicular mass composed of sheets of uniform round cells with prominent nucleoli, divided by lymphocyte-infiltrated fibrous septa; cryptorchidism is a major predisposing factor.

Question 44 — Answer: B. Lichen Sclerosus

The description is pathognomonic for lichen sclerosus:

Clinical: White, parchment-like or "cigarette-paper" textured papules/macules that coalesce — classically on vulva of postmenopausal women

Histology (per Robbins):

Epidermal thinning (atrophy)
Superficial hyperkeratosis
Homogenized/hyalinized dermal collagen (fibrosis) in the upper dermis
Scant perivascular mononuclear (lymphocytic) infiltrate below the fibrotic zone

Comparing the other options:

Lichen simplex chronicus: shows epidermal thickening (acanthosis) and hyperkeratosis — opposite of thinning
VIN (Vulvar Intraepithelial Neoplasia): shows dysplastic epithelial cells, koilocytosis (if HPV-related)
Condyloma acuminata: HPV-induced warty growth with koilocytosis

Robbins Basic Pathology — Female Genital Tract: Lichen sclerosus is characterized by epidermal atrophy, hyperkeratosis, and upper dermal homogenization/fibrosis with a sparse lymphocytic infiltrate; it presents as white parchment-like vulvar plaques and carries a small risk of squamous cell carcinoma.

45. Which of the following breast cancer type and microscopic feature is CORRECTLY paired? A. Colloid carcinoma: large lakes of mucin with small islands of tumor cells B. Scirrhous carcinoma: syncytial sheets of pleomorphic cells with lymphoid stroma C. Invasive lobular carcinoma: well-formed tubules with apical snouts D. Papillary carcinoma: papillary structures with intact myoepithelial layer 46. A 43-year-old woman, during breast self-examination, identifies a nodule in her left breast. She subsequently undergoes a lumpectomy. A pathologist determines that the malignant tumor is of glandular origin. Which of the following is TRUE? A. A colloid carcinoma would have a worse prognosis than ductal carcinoma. B. She most likely has a BRCA1 or BRCA2 mutation. C. Skin involvement is a good sign. D. If the tumor is ER/PR positive, it has a better prognosis. 47. The edema in Nephrotic Syndrome is explained by which of the following statements? A. There is water retention because of increased solute retention B. Urinary protein is loss due to injury in the glomerulus C. Fluid accumulation results from renal insufficiency D. Sodium and water absorption is inappropriate 48. Crescent formation is produced by the proliferation of which component of the glomerulus? A. Endothelial cells C. Parietal epithelial cells B. Mesangial cells D. Podocytes 49. A 10-year-old girl presents with generalized edema and proteinuria. Urinalysis showed 3+ protein and oval fat bodies. Kidney biopsy was done and revealed normal glomerulus on H&E stain. Immunofluorescence also showed normal results. What would be the expected finding on electron microscopy? A. Subendothelial deposits C. Subepithelial deposits B. Loss of foot processes D. Normal electron microscopic findings 50. A 40-year-old man presents with hemoptysis and renal failure. He has antibodies to collagen type IV that react with glomerular basement membranes in a linear manner. What is the most likely diagnosis? A. Systemic lupus erythematosus C. Serum sickness B. Graft vs. Host reaction D. Goodpasture syndrome

Medical Text Search

breast cancer types colloid carcinoma mucinous invasive lobular scirrhous medullary histologic features microscopy

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nephrotic syndrome minimal change disease foot process effacement electron microscopy proteinuria oval fat bodies

GradeResponse

Here are the answers based on Robbins Textbook of Pathology:

Question 45 — Answer: A. Colloid carcinoma: large lakes of mucin with small islands of tumor cells

Robbins describes each breast carcinoma subtype as follows:

Subtype	Correct Microscopic Description
Colloid (Mucinous) carcinoma	Large extracellular lakes of mucin containing small islands/clusters of tumor cells ✅
Medullary carcinoma	Syncytial sheets of pleomorphic cells with prominent lymphoid/plasma cell stroma
Scirrhous (Invasive Ductal NOS) carcinoma	Single-file cords of cells in a dense desmoplastic stroma — NOT syncytial sheets
Invasive lobular carcinoma	Single-file (Indian file) pattern of cells; signet ring cells; not well-formed tubules
Tubular carcinoma	Well-formed angulated tubules with apical snouts
Papillary carcinoma	Papillary fronds — but the myoepithelial layer is characteristically ABSENT (unlike benign papillomas)

Errors in other options:

B — syncytial sheets with lymphoid stroma = medullary carcinoma, not scirrhous
C — well-formed tubules with apical snouts = tubular carcinoma, not lobular
D — papillary carcinoma has absent myoepithelial layer (presence of myoepithelium = benign papilloma)

Robbins Basic Pathology — Breast: Mucinous (colloid) carcinoma is characterized by abundant extracellular mucin forming lakes that contain floating nests of tumor cells; it carries a favorable prognosis.

Question 46 — Answer: D. If the tumor is ER/PR positive, it has a better prognosis

Robbins is explicit on this point:

Estrogen receptor (ER) and Progesterone receptor (PR) positivity = better prognosis because:
- Tumors respond to hormonal therapy (tamoxifen, aromatase inhibitors)
- ER/PR-positive tumors tend to be better differentiated and less aggressive

Evaluating the other options:

A — Colloid carcinoma actually has a better prognosis than invasive ductal carcinoma NOS, not worse
B — Only ~5–10% of breast cancers are due to hereditary BRCA1/BRCA2 mutations; the majority (~85–90%) are sporadic — so "most likely" is incorrect
C — Skin involvement (peau d'orange, skin nodules, inflammatory carcinoma) is a poor prognostic sign, indicating locally advanced or T4 disease

Robbins Basic Pathology — Breast: ER/PR positivity in breast carcinoma confers a better prognosis and predicts response to hormonal therapy; it is one of the most important favorable prognostic markers.

Question 47 — Answer: B. Urinary protein loss due to injury in the glomerulus

Robbins explains the pathophysiology of edema in nephrotic syndrome as a direct sequence:

Glomerular injury → increased permeability of the glomerular filtration barrier
→ Massive proteinuria (>3.5 g/day in adults)
→ Hypoalbuminemia (decreased plasma oncotic pressure)
→ Fluid shifts from intravascular to interstitial compartment → generalized edema (anasarca)
→ Secondary activation of RAAS → sodium and water retention (compensatory, not primary)

Option A: Water retention from increased solute = mechanism of isotonic expansion, not nephrotic edema
Option C: Renal insufficiency = nephritic/chronic kidney disease mechanism
Option D: Inappropriate Na⁺/H₂O absorption is a secondary consequence, not the primary mechanism

Robbins Basic Pathology — Kidney: The edema of nephrotic syndrome is initiated by glomerular injury causing proteinuria → hypoalbuminemia → reduced oncotic pressure → transudation of fluid into tissues.

Question 48 — Answer: C. Parietal epithelial cells

Robbins clearly identifies the cellular origin of crescents:

Crescents are the histologic hallmark of rapidly progressive (crescentic) glomerulonephritis (RPGN). They form in Bowman's space by proliferation of:

Parietal epithelial cells (lining Bowman's capsule) — the primary contributors ✅
Infiltrating monocytes/macrophages — secondary contributors

The crescents compress and obliterate the glomerular tuft. Fibrin deposition from disrupted capillary loops triggers parietal epithelial proliferation.

Endothelial cells: proliferate in post-streptococcal GN (endocapillary proliferation), not crescent formation
Mesangial cells: proliferate in IgA nephropathy / mesangioproliferative GN
Podocytes: effaced in nephrotic syndrome; not the source of crescents

Robbins Basic Pathology — Kidney: Crescents in RPGN are formed by proliferation of parietal epithelial cells of Bowman's capsule along with infiltrating macrophages, filling Bowman's space and compressing the glomerular tuft.

Question 49 — Answer: B. Loss of foot processes (effacement)

The clinical scenario describes:

10-year-old girl
Generalized edema + nephrotic-range proteinuria (3+)
Oval fat bodies in urine
Normal H&E (light microscopy)
Normal immunofluorescence

This is the classic triad of Minimal Change Disease (MCD) / Lipoid Nephrosis — the most common cause of nephrotic syndrome in children.

Robbins states that MCD is defined by:

Light microscopy: normal glomeruli
Immunofluorescence: negative / normal
Electron microscopy: diffuse effacement (loss) of podocyte foot processes ✅ — the diagnostic hallmark

No immune deposits are seen (ruling out subendothelial deposits of membranoproliferative GN, or subepithelial "spike and dome" deposits of membranous nephropathy).

Robbins Basic Pathology — Kidney: Minimal change disease shows no abnormality on light microscopy or immunofluorescence; electron microscopy reveals diffuse effacement of podocyte foot processes, which is the pathognomonic and sole diagnostic finding.

Question 50 — Answer: D. Goodpasture Syndrome

The combination of:

Hemoptysis (pulmonary hemorrhage)
Renal failure (glomerulonephritis)
Anti-type IV collagen antibodies (anti-GBM antibodies)
Linear immunofluorescence along the GBM

is the textbook definition of Goodpasture syndrome.

Robbins explains:

Auto-antibodies target the α3 chain of type IV collagen in both the glomerular and alveolar basement membranes
Linear IgG deposits on immunofluorescence (vs. granular/lumpy deposits in immune complex diseases)
Causes crescentic (RPGN Type I) glomerulonephritis + diffuse alveolar hemorrhage

Distinguishing from other options:

SLE: granular "full house" immunofluorescence; anti-dsDNA antibodies; not linear
Serum sickness: immune complex (Type III) — granular deposits; no anti-GBM antibodies
Graft vs. Host: T-cell mediated; no anti-GBM antibodies

Robbins Basic Pathology — Kidney: Goodpasture syndrome is caused by anti-GBM antibodies directed against the α3 chain of type IV collagen, producing linear IgG deposits, crescentic glomerulonephritis, and pulmonary hemorrhage.

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