note on lymphadenitis briefly

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Here is a concise note on lymphadenitis:

Lymphadenitis

Definition

Inflammation of lymph nodes in response to infection or other inflammatory stimuli. Lymph nodes act as defensive barriers, and any immune response against foreign antigens can cause nodal enlargement (lymphadenopathy).

Classification

1. Acute Nonspecific Lymphadenitis

Causes: Pyogenic bacteria, systemic viral infections (especially in children), bacteremia
Common sites:
- Cervical — drainage from dental/tonsillar infections
- Axillary/Inguinal — infections of the extremities
- Mesenteric — acute appendicitis, gut inflammation, viral GI infections
Clinical features: Enlarged, tender nodes; fever, anorexia, malaise; overlying skin may be red; nodes become fluctuant if abscess forms
Morphology:
- Nodes are swollen, gray-red, engorged
- Large reactive germinal centers with numerous mitotic figures
- Neutrophilic infiltrate around follicles and within sinuses
- Severe infection → follicular center necrosis → abscess → draining sinuses
Treatment: Directed at the primary focus (e.g., tonsillitis, dental abscess)

2. Chronic Nonspecific Lymphadenitis

Assumes one of three histological patterns:

Pattern	Mechanism	Key Causes
Follicular hyperplasia	B-cell activation in germinal centers	Rheumatoid arthritis, toxoplasmosis, early HIV
Paracortical hyperplasia	T-cell zone reaction; immunoblasts efface B-cell follicles	EBV, vaccinations, drug reactions (phenytoin)
Sinus histiocytosis	Distension of sinusoids; hypertrophy of lining endothelium	Carcinomas draining to regional nodes

Chronic cervical lymphadenopathy causes include TB, malignancy (squamous cell carcinoma in older adults), lymphoma, HIV

3. TB Lymphadenitis (Scrofula)

Most common form of extrapulmonary TB
Preferentially involves posterior cervical and supraclavicular nodes (painless)
Occurs often without clinical pulmonary disease
More common in children and adolescents; slight female predominance
Disease progression → suppuration → sinus tract formation
In the USA, scrofula is more often caused by non-tuberculous mycobacteria than M. tuberculosis

4. Filarial Lymphadenitis

Acute episodes due to dying adult worms (Wuchereria bancrofti, Brugia malayi)
Painful inguinal node enlargement with erythema, fever, chills; may recur
Can be complicated by epididymitis/orchitis
Repeated episodes → lymphatic dilation → chronic lymphedema (elephantiasis)

Key Distinguishing Point: Follicular Hyperplasia vs. Follicular Lymphoma

Reactive follicular hyperplasia is distinguished from follicular lymphoma by:

Preservation of lymph node architecture
Variation in size/shape of germinal centers
Mixed lymphocyte population (varying shapes/sizes)
Prominent mitotic activity and macrophage phagocytosis (tingible body macrophages)

Sources: Robbins & Kumar Basic Pathology; Robbins, Cotran & Kumar Pathologic Basis of Disease; Bailey and Love's Surgery 28th Ed.; Goldman-Cecil Medicine

write a note on wilson`s disease

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Wilson's Disease

Also known as: Hepatolenticular degeneration

Definition & Genetics

Wilson's disease is an autosomal recessive disorder caused by loss-of-function mutations in the ATP7B gene (chromosome 13q). The ATP7B protein is a copper-transporting P-type ATPase located in the trans-Golgi network and lysosomes of hepatocytes. Mutations impair:

Copper excretion into bile (major route of copper elimination)
Copper incorporation into apoceruloplasmin → low serum ceruloplasmin

Result: toxic copper accumulation in liver, brain, cornea, kidneys, bones, and joints.

Copper metabolism and ATP7B mutation in Wilson's disease

Copper metabolism and the consequences of ATP7B mutation — Robbins & Kumar Basic Pathology

Epidemiology

Prevalence ~1 in 30,000
Symptoms typically appear between 6 and 40 years of age
Over 300 pathogenic mutations identified; most common: His1069Glu (~40% of cases in certain ethnic groups)

Pathogenesis

Normally, 40–60% of ingested copper (2–5 mg/day) is absorbed in the duodenum and transported to the liver bound to albumin. In hepatocytes, ATP7B:

Transfers copper to apoceruloplasmin (in trans-Golgi) → secreted as ceruloplasmin into blood
Transports excess copper via lysosomes into bile canaliculi

In Wilson's disease, both pathways fail → copper accumulates in hepatocyte cytoplasm → ↑ROS → hepatocyte injury → copper spills into blood → deposits in other organs.

Clinical Presentation

About 1/3 present with each of: hepatic disease, neurological features, psychiatric symptoms.

Hepatic (most common initial presentation in children)

Stage	Features
Early	Steatohepatitis, elevated transaminases
Intermediate	Chronic active hepatitis, fibrosis
Advanced	Cirrhosis, portal hypertension
Acute/fulminant	Acute liver failure with Coombs-negative hemolytic anemia; typically in 2nd decade

Clue for fulminant WD: serum ALP/total bilirubin < 4 AND AST/ALT > 2.2

Neurological (extrapyramidal predominant)

Tremor (may have wing-beating character), chorea, dystonia
Dysarthria, dysphagia, ataxia, gait disturbance
Fixed "sardonic" smile
Seizures (minority)
MRI shows abnormal T2 signal in putamen, midbrain, pons, thalamus, cerebellum

Neuropsychiatric

Present in ≥50% early in the course; ~70% develop symptoms long-term
Personality/mood changes (most common), depression (~30%), bipolar spectrum (~20%)
Psychosis; increased sensitivity to neuroleptics
Suicidal ideation (5–15%)

Ophthalmologic

Kayser-Fleischer (KF) rings — green-to-brown copper deposits in Descemet membrane at corneal limbus; best seen on slit-lamp
- Present in 98% of neurological WD, 80% of all cases
Sunflower cataracts — copper in lens

Other organs

Renal tubular dysfunction (Fanconi syndrome), renal stones
Hemolytic anemia
Osteoporosis, arthropathy
Hypoparathyroidism

Morphology

Liver

Stage	Histology
Early	Glycogen-filled nuclei, microvesicular + macrovesicular steatosis
Chronic	Portal mononuclear infiltrates, interface hepatitis, Mallory bodies, periportal fibrosis
Fulminant	Coagulative necrosis, microvesicular fat, Kupffer cell pigment, established cirrhosis
Late	Mixed micro- and macronodular cirrhosis

Electron microscopy: pleomorphic, enlarged mitochondria with widened intracristal spaces (early/characteristic finding)
Histochemical copper stains unreliable; quantitative liver copper > 250 μg/g dry weight is diagnostic (but only ~80% sensitive)

Brain

Toxic injury predominantly to basal ganglia (putamen most affected)

Diagnosis

Test	Finding	Notes
Serum ceruloplasmin	↓ (<20 mg/dL)	Hallmark; also low in malnutrition, nephrotic syndrome
24-h urine copper	↑ (>100 μg/day)	Most specific test
Liver copper (biopsy)	>250 μg/g dry wt	Most sensitive test
KF rings (slit-lamp)	Present	98% in neurological WD
Serum copper	Variable	Not diagnostically useful
MRI brain	T2 hyperintensity basal ganglia	Neurological WD
Genetic testing	ATP7B mutation	Useful for family screening; >300 mutations makes it complex

A scoring system (Leipzig score) assists diagnosis when results are borderline.

Treatment

Wilson's disease is uniformly fatal without therapy. Goals: reduce copper burden + prevent further retention.

Medical

Indication	Preferred Treatment
Initial hepatic disease	Trientine (preferred) or D-penicillamine + zinc
Initial neurological	Tetrathiomolybdate (clinical trial), trientine ± zinc
Presymptomatic	Zinc or trientine
Maintenance	Zinc or trientine
Pregnancy	Zinc (safest)
Acute liver failure	Plasmapheresis → liver transplantation

Chelating agents:

Trientine (triethylenetetramine): now preferred at most centers; better tolerated; dose 10–20 mg/kg/day (1–2 g/day) in 2–3 divided doses before meals
D-Penicillamine: 1–2 g/day; add pyridoxine 25 mg/day (antipyridoxine effect); 20–50% of neurological patients worsen acutely on initiation
Start at ¼–½ target dose and titrate over several weeks

Zinc: inhibits intestinal copper absorption by inducing metallothionein in enterocytes; preferred for maintenance and pregnancy

Monitoring: CBC, urinalysis, LFTs weekly for first month; 24-h urinary copper every 6–12 months; target <500 μg/day after several years of chelation.

Surgical

Liver transplantation — curative; indicated for fulminant liver failure or advanced cirrhosis unresponsive to medical therapy; corrects the metabolic defect

Prognosis

Early diagnosis and lifelong treatment dramatically alter the course
Neurological and psychiatric symptoms improve with treatment (but ~70% still develop psychiatric features long-term)
MRI changes may partially reverse with effective therapy

Sources: Robbins & Kumar Basic Pathology; Yamada's Textbook of Gastroenterology 7th ed.; Bradley and Daroff's Neurology in Clinical Practice; Sleisenger & Fordtran's GI and Liver Disease

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