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Comprehensive ENT Notes: 13 Topics

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1. VESTIBULAR SCHWANNOMA (Acoustic Neuroma)

Definition

Epidemiology

• Incidence: ~1-2 per 100,000 per year
• Peak age: 40-60 years
• Usually unilateral; bilateral VS is pathognomonic of Neurofibromatosis type 2 (NF2)
• NF2: autosomal dominant mutation on chromosome 22 (merlin/schwannomin gene)

Types / Classification

Etiology / Pathogenesis

• Sporadic: loss of function of the NF2 tumor suppressor gene on chromosome 22q12 (merlin protein)
• NF2: germline mutation - bilateral VS, meningiomas, ependymomas
• Ionizing radiation (prior radiotherapy to the head) is a recognized risk factor
• The tumor arises at the junction of central and peripheral myelin (Obersteiner-Redlich zone) at the glial-Schwann cell transition near the porus acousticus

Pathophysiology

• Slow, centrifugal growth within the IAC causes progressive compression of cochlear and vestibular nerve fibers
• Extension into the CPA cistern leads to compression of CN V (trigeminal - first sensory loss), CN VII (facial palsy - late), and eventually the brainstem and cerebellum
• Cystic degeneration in larger tumors causes rapid expansion
• Obstruction of the 4th ventricle leads to obstructive hydrocephalus in very large tumors

Clinical Features

• Unilateral, progressive sensorineural hearing loss (SNHL) - most common presentation (95%)
• Tinnitus (unilateral, high-pitched)
• Disequilibrium / imbalance (not true vertigo, as the slow growth allows central compensation)

• Trigeminal hypoesthesia/numbness (first CN affected by CPA extension)
• Facial weakness (CN VII) - late and uncommon unless large
• Headache, cerebellar ataxia, diplopia
• Hydrocephalus - papilledema, nausea, vomiting

Investigations

• Pure tone audiogram: asymmetric SNHL (worse at high frequencies)
• Speech discrimination score: disproportionately poor (rollover phenomenon)
• ABR (Auditory Brainstem Response): prolonged I-V interpeak latency, most sensitive screening test

• MRI with gadolinium contrast: investigation of choice
  • Thin-section T2 (CISS/FIESTA): shows tumor in relation to nerves in CSF
  • Post-contrast T1: enhances homogeneously (small tumors); heterogeneously (larger/cystic)
  • Produces "ice cream cone" appearance at IAC/CPA junction
• CT temporal bone: shows IAC erosion/widening (less sensitive than MRI)

• Caloric testing: canal paresis on affected side
• ENG/VNG: reduced vestibular function ipsilaterally

Management

• Translabyrinthine: no hearing preservation; best access; used when hearing is already poor
• Retrosigmoid/suboccipital: hearing preservation possible; good for intracanalicular tumors
• Middle fossa craniotomy: hearing preservation; best for small intracanalicular tumors

Complications

• Progressive SNHL (deaf ear)
• Facial nerve palsy (CN VII damage - intraoperative)
• CSF leak
• Meningitis
• Obstructive hydrocephalus
• Brainstem compression (large untreated tumors)
• Tumor recurrence/regrowth post-treatment

Differential Diagnosis (CPA/IAC lesions)

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2. CEREBELLOPONTINE ANGLE (CP ANGLE) TUMORS

Definition

Epidemiology of CPA Tumors

Clinical Features (CPA Syndrome)

• CN VIII: SNHL, tinnitus, imbalance (earliest)
• CN V: facial numbness/hypoesthesia (first CN affected by CPA mass)
• CN VII: facial weakness (late)
• Cerebellar: ipsilateral ataxia, dysdiadochokinesis
• CN IX/X/XI: dysphagia, hoarseness (jugular foramen extension)
• Hydrocephalus: headache, papilledema (compression of 4th ventricle)

Specific Tumors

• Definition: benign tumor of arachnoid cap cells; second most common CPA tumor
• MRI: broad dural base, homogeneous enhancement, "dural tail" sign; rarely enters IAC
• Management: observation for small lesions; surgery (microsurgical excision); SRS for recurrence or inoperable tumors

• Definition: congenital inclusion cyst lined by stratified squamous epithelium; slowly expands by desquamation
• MRI: follows CSF on T1/T2 but shows diffusion restriction (bright DWI) - pathognomonic
• Clinical: "pearly tumor"; crawls around cranial nerves rather than displacing them
• Management: surgical excision (complete removal is curative; recurrence if incomplete)

• Follows CSF signal on all MRI sequences; no enhancement; no diffusion restriction
• Usually incidental; may cause pressure symptoms

• Arises from paraganglionic tissue at jugular foramen
• MRI: "salt and pepper" appearance; pulsatile tinnitus + CN IX/X/XI palsies
• Management: surgery ± preoperative embolization; SRS for elderly/surgical risks

• MRI: high T1 AND high T2 (unique among CPA lesions due to methemoglobin); no enhancement
• Management: surgical drainage

Investigations

• MRI brain with gadolinium (gold standard)
• Audiometry + ABR
• CT temporal bone (for bony erosion)
• Formal cranial nerve testing

Management Principles

• Multidisciplinary: neurosurgery + otolaryngology
• Approaches: retrosigmoid, translabyrinthine, middle fossa
• Observation: for small, asymptomatic lesions in elderly
• SRS: for residual/recurrent disease, poor surgical candidates

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3. OTOSCLEROSIS

Definition

Types / Classification

Etiology

• Genetic: autosomal dominant with variable penetrance (~25-40%); multiple loci implicated (OTSC1 on 15q25, OTSC2 on 7q34, OTSC3 on 6p21, etc.)
• Measles virus (paramyxovirus): viral RNA found in otosclerotic foci; measles vaccination has reduced incidence
• Hormonal: exacerbation during pregnancy (estrogen increases bone resorption) - fluoride counteracts this
• Autoimmune: type II collagen antibodies detected

Pathogenesis

1. Osteoclastic resorption of normal lamellar endochondral bone at the fissula ante fenestram
2. Replacement by highly cellular, vascular spongy "otospongiosis" (active phase - histologically resembles angioblastic tissue; flamingo-pink histology)
3. Mineralization to dense sclerotic bone (mature phase)
4. Progressive encroachment on oval window niche → annular ligament involvement → stapedial fixation
5. Cochlear involvement: demineralization of cochlear capsule → SNHL

Clinical Features

• Paracusis Willisii: paradoxical improvement in hearing in noisy environments (background noise forces others to raise voice; masking bone conduction tinnitus)
• Progressive conductive hearing loss: bilateral, asymmetric, onset 2nd-4th decade
• Tinnitus: low-frequency; often the initial complaint
• Vertigo: uncommon; suggests retrofenestral involvement
• Schwartz sign: flamingo-pink blush seen through intact tympanic membrane on otoscopy (active otosclerosis - increased vascularity of promontory)
• Tympanic membrane: intact and normal
• Tympanometry: reduced compliance (As pattern - shallow As type curve); absent stapedius reflex

Audiological Findings

• Carhart's notch: characteristic dip at 2000 Hz in bone conduction audiogram (mechanical, not sensorineural - resolves post-stapedectomy)
• Audiogram: rising CHL (better at high frequencies initially)
• ABG (air-bone gap): 20-60 dB
• Speech discrimination: excellent (distinguishes from cochlear cause)

Investigations

• Pure tone audiogram: CHL + Carhart's notch at 2000 Hz
• Tympanometry: As (reduced compliance); absent stapedial reflexes
• CT temporal bone: best imaging; shows demineralization around oval window, "double ring" (halo) around cochlea in cochlear otosclerosis
• Electrocochleography: to check inner ear function before surgery (especially bilateral)

Management

• Sodium fluoride: promotes remineralization of otosclerotic foci; arrests progression; 25 mg/day for active disease (Schwartz sign present); not curative
• Bisphosphonates: emerging evidence
• Hearing aids: valid alternative; offered before surgery

• Stapedotomy (preferred over stapedectomy for >35 years): small fenestra (0.6 mm) created in stapes footplate; prosthesis (Teflon-platinum or titanium) crimped to incus
• Stapedectomy: complete footplate removal; rarely indicated now; reserved for complications of stapedotomy
• Contraindications: only hearing ear, active vestibular disease, poor general health, "dead ear" in contralateral side

Complications of Surgery

• Sensorineural hearing loss (dead ear) - most feared
• Perilymph fistula
• Tympanic membrane perforation
• Prosthesis displacement or dislocation
• Taste disturbance (chorda tympani injury)
• Vertigo (transient)
• Reparative granuloma

Differential Diagnosis

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4. MYRINGITIS BULLOSA (Bullous Myringitis)

Definition

Etiology

• Not fully established - etiology remains controversial
• Initially associated with influenza virus (early studies)
• Mycoplasma pneumoniae: Rifkin et al. induced bullous myringitis in nearly 50% of healthy subjects inoculated with M. pneumoniae
• However, Merifield and Miller found no consistent antibody titer changes to M. pneumoniae or common respiratory viruses in affected patients
• Typically follows a nonspecific upper respiratory tract infection
• May represent a nonspecific inflammatory response of the tympanic membrane rather than a distinct entity
• Other organisms: Streptococcus pneumoniae, H. influenzae, viral (respiratory syncytial virus)

Pathophysiology

• Bullae form between the epidermal and fibrous layers of the tympanic membrane
• Inflammatory exudate (serous or hemorrhagic) collects under the epithelium
• Middle ear effusion may coexist
• Cochlear involvement can cause transient sensorineural hearing loss via spread of inflammation to the perilymph

Clinical Features

• Severe, acute otalgia - most prominent feature; disproportionate to otoscopic findings
• Tympanic membrane: bloodshot, red, with 1 or more hemorrhagic or serous bullae
• Hearing loss: conductive (if middle ear effusion) + sensorineural in 67% of cases (Hoffman & Shepsman review of 21 ears)
• SNHL: usually transient; most patients recover full hearing
• Fever, malaise (if associated upper respiratory infection)
• Otorrhoea: if bullae rupture
• Typically unilateral
• Tympanic membrane otherwise intact (no perforation)

Investigations

• Otoscopy: hemorrhagic/serous bullae on TM - diagnostic
• Audiometry: mixed HL (conductive + sensorineural component)
• Tympanometry: flat (type B) if effusion present
• Culture: exudate from ruptured bullae; often sterile or mixed flora

Management

• Decompression of bullae (myringotomy/lancing): immediate pain relief - traditional treatment
• Oral analgesics (NSAIDs, paracetamol) for pain management
• Antibiotics: given empirically to cover bacterial causes (amoxicillin-clavulanate or azithromycin for M. pneumoniae coverage)
• SNHL management: if sensorineural component is present:
  • Treat aggressively with antibiotics + systemic corticosteroids (prednisone 1 mg/kg/day for 7 days, then tapered) - treat as complication of otitis media
• Myringotomy: if middle ear effusion accompanies bullae
• Prognosis: generally excellent; hearing loss usually resolves completely

Complications

• Transient SNHL (usually reversible)
• Permanent SNHL (rare)
• Perforation of tympanic membrane (from rupture)
• Secondary bacterial otitis media

Differential Diagnosis

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5. GRANULOMATOUS DISEASES OF THE NOSE

Definition

Classification

• Leishmaniasis (Leishmania spp.)

• Extranodal NK/T-cell lymphoma (midline lethal granuloma)

Selected Conditions in Detail

Rhinoscleroma

• Chronic granulomatous infection caused by Klebsiella rhinoscleromatis
• Stages: catarrhal (rhinitis) → proliferative (Mikulicz cells - foamy macrophages containing bacilli; Russell bodies - plasma cells) → sclerotic (fibrosis, stenosis)
• Investigations: biopsy, culture, Giemsa stain (bacilli in Mikulicz cells)
• Treatment: prolonged antibiotics (ciprofloxacin, tetracycline); surgery for fibrotic stenosis

Sarcoidosis

• Non-caseating epithelioid granulomas; Schaumann bodies (calcified inclusions); Asteroid bodies
• Nasal: crusting, septal perforation, lupus pernio (violaceous skin lesion)
• Diagnosis: tissue biopsy; elevated serum ACE; chest X-ray (bilateral hilar adenopathy)
• Treatment: systemic corticosteroids

GPA (Wegener's Granulomatosis)

• Classic triad: necrotizing granulomas of upper and lower respiratory tract + necrotizing glomerulonephritis
• Nasal: septal perforation → saddle nose deformity; crusting; epistaxis; persistent nasal discharge
• Diagnosis: cANCA (anti-PR3) - highly specific; tissue biopsy
• Treatment: induction with cyclophosphamide + prednisolone; maintenance with methotrexate/azathioprine

Leprosy (Nasal)

• Mycobacterium leprae; tropism for cooler tissues (nasal skin and mucosa)
• Nasal: presents early; nasal stuffiness, epistaxis, collapse of nasal bridge
• Histology: Virchow cells (foamy macrophages packed with bacilli) - lepromatous type
• Diagnosis: slit skin smear; biopsy
• Treatment: multidrug therapy (rifampicin + dapsone ± clofazimine)

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6. CHRONIC RHINOSINUSITIS (CRS) WITH EPOS CLASSIFICATION

Definition

• Nasal blockage/congestion AND/OR nasal discharge (anterior/posterior)
• Facial pain/pressure
• Reduction/loss of smell
• Plus: endoscopic signs (polyps, mucopurulent discharge, mucosal edema in middle meatus) OR CT changes (mucosal changes in OMC and/or sinuses)

EPOS Classification

1. Type 2 inflammation (Th2 skewed) - associated with CRSwNP, asthma, aspirin sensitivity, NSAID-exacerbated respiratory disease (NERD), eosinophilia, high IL-4/IL-5/IL-13
2. Non-Type 2 inflammation (Th1/Th17) - associated with CRSsNP, neutrophilic inflammation, fibrosis
3. Primary CRS (no obvious underlying cause) vs. Secondary CRS (polyps secondary to fungal ball, inverted papilloma, etc.)
4. Localized CRS vs. Diffuse CRS

• Mild: VAS 0-3
• Moderate: VAS >3-7
• Severe: VAS >7-10

Pathophysiology

• Intense edematous stroma in sinonasal epithelium
• Albumin deposition, pseudocyst formation
• Subepithelial/perivascular eosinophilic infiltrate
• High IL-5 and eosinophil cationic protein (ECP)
• Staphylococcal superantigen hypothesis: S. aureus enterotoxins act as polyclonal T-cell activators triggering Th2 response

• Fibrosis, basement membrane thickening
• Goblet cell hyperplasia
• Mononuclear cell infiltration
• IFN-γ predominance; low ECP

• Ostiomeatal complex (OMC) obstruction → impaired mucociliary clearance → bacterial colonization → persistent mucosal inflammation
• Epithelial barrier dysfunction
• Microbiome dysbiosis

Etiology

• Ostiomeatal complex obstruction (septal deviation, concha bullosa, mucosal edema)
• Allergy (IgE-mediated sensitization)
• Bacterial biofilms (Staphylococcus aureus, Pseudomonas, Haemophilus)
• Aspirin/NSAID hypersensitivity (Samter's triad: CRSwNP + asthma + aspirin sensitivity)
• Cystic fibrosis (CFTR mutation)
• Ciliary dyskinesia (Kartagener syndrome)
• Immunodeficiency (IgA/IgG deficiency)
• Dental infections (odontogenic sinusitis)
• Fungal (eosinophilic fungal rhinosinusitis - EFRS)

CT Patterns (Babbel classification)

Clinical Features

• Nasal congestion/blockage
• Mucopurulent discharge (anterior/posterior nasal drip)
• Facial pain/pressure/fullness
• Hyposmia or anosmia
• Headache
• Symptoms for >12 weeks continuously
• Endoscopy: middle meatus edema, mucopurulence, polyps (CRSwNP)

Investigations

• Nasal endoscopy: visualizes OMC, polyps, discharge
• CT paranasal sinuses (gold standard imaging): Lund-Mackay score (0-24); osteitis (bone thickening)
• Skin prick test / RAST: allergy assessment
• Nasal cytology: eosinophils (allergic/Th2 type) vs. neutrophils (infectious)
• Cystic fibrosis testing (sweat chloride, CFTR genotype) if bilateral diffuse disease in children
• ANCA, ACE: if granulomatous disease suspected
• Culture (endoscopically directed): to guide antibiotic therapy
• Biopsy: if neoplasm suspected or atypical course

Management

1. Saline irrigation (isotonic/hypertonic): mainstay of conservative treatment
2. Intranasal corticosteroids (INCS): first-line for CRSwNP and CRSsNP (mometasone, fluticasone, budesonide)
3. Oral corticosteroids: short course (Prednisone 0.5-1 mg/kg/day x 5-14 days) for CRSwNP exacerbations; nasal polyp shrinkage
4. Antibiotics:
   • Acute exacerbations: amoxicillin-clavulanate or doxycycline (2 weeks)
   • Long-term low-dose macrolides (roxithromycin/clarithromycin x 3 months) for CRSsNP without eosinophilia - anti-inflammatory mechanism
5. Dupilumab (IL-4Rα blocker, blocking IL-4 + IL-13): biologic for severe CRSwNP; EPOS recommends as add-on for type 2 CRSwNP refractory to surgery
6. Anti-IgE (omalizumab), Anti-IL-5 (mepolizumab): add-on biologics

• Indication: failure of medical therapy (3 months)
• Goal: restore drainage and ventilation of sinuses; OMC clearance
• Procedures: uncinectomy, maxillary antrostomy, ethmoidectomy, sphenoidotomy, frontal sinusotomy (Draf I/II/III)
• Lund-Mackay score guides extent of surgery

Complications

• Orbital: periorbital cellulitis, subperiosteal abscess, orbital abscess, cavernous sinus thrombosis
• Intracranial: meningitis, epidural abscess, subdural empyema, brain abscess, Pott's puffy tumor
• Mucocele formation
• Anosmia

Differential Diagnosis

• Allergic rhinitis (no sinus changes on CT)
• Acute recurrent rhinosinusitis
• Granulomatous diseases (GPA, sarcoidosis)
• Inverted papilloma
• Sinonasal malignancy
• CSF rhinorrhea
• Odontogenic sinusitis (unilateral; maxillary)

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7. ACUTE FUNGAL RHINOSINUSITIS (AIFS - Acute Invasive Fungal Sinusitis)

Definition

Types of Fungal Sinusitis (full classification)

Etiology / Microbiology

• Fast-growing, coenocytic molds
• Irregular non-septate or pauci-septate hyphae branching at wide angles (~90°)
• Order Mucorales: Rhizopus (most common), Mucor, Rhizomucor, Absidia, Cunninghamella
• Mucormycosis: specific term for infection by Mucorales - NOT synonymous with AIFS unless culture-confirmed

• Aspergillus fumigatus (most common), flavus, niger, terreus
• Septate hyphae, branching at acute angles (~45°)
• Ubiquitous; saprophytic under normal conditions

• Mucorales growth facilitated by acidic conditions via ketone reductase enzyme
• Abnormal transferrin binding in diabetics → free iron available for fungal growth
• Deferoxamine (iron-chelating agent in dialysis patients) acts as siderophore for Rhizopus - dramatically increases risk

Risk Factors (Immunocompromised States)

1. Hematologic malignancies (leukemia, lymphoma, bone marrow transplantation)
2. Chemotherapy-induced neutropenia
3. Chronic immunosuppression (solid organ transplantation, prolonged steroids)
4. Diabetes mellitus with ketoacidosis (DKA) - mucormycosis is classically associated
5. Advanced HIV/AIDS with neutrophil dysfunction
6. Dialysis patients receiving deferoxamine

Pathogenesis

1. Fungal spores inhaled → deposited in sinonasal mucosa (normally cleared by functioning neutrophils/macrophages)
2. In immunocompromised host: germination and hyphal invasion of mucosa
3. Angioinvasion: hyphae penetrate vessel walls → thrombosis → ischemia → necrosis (black eschar)
4. Spread: perineural (along trigeminal branches), direct extension through bony walls, orbital apex, cavernous sinus, intracranial
5. Rhinocerebral pattern: nasal cavity → ethmoid → orbit → cavernous sinus → brain

Clinical Features

• Rhinosinusitis symptoms: nasal obstruction, mucous discharge, facial pressure
• Fever, facial numbness (infraorbital nerve - premaxillary numbness is an early warning sign)

• Black eschar or white necrotic debris on nasal mucosa or turbinates (ischemic necrosis)
• Pale, bloodless mucosa that does not bleed on probing (anesthesia to manipulation)
• Proptosis, periorbital edema/ecchymosis
• Ophthalmoplegia (CN III, IV, VI involvement)
• Blindness (optic nerve involvement)
• Hard/soft palate necrosis (involvement of palate blood supply)
• Altered mental status (intracranial extension)
• Cranial nerve palsies

Investigations

• Operative endoscopy and biopsy > bedside evaluation for sensitivity
• Frozen section biopsies: key for rapid intraoperative diagnosis
• Optimal biopsy site: antero-inferior portion of middle turbinate (85% sensitivity, 100% specificity)
• Multiple biopsies enhance sensitivity
• Histological stains:
  • Silver stain (GMS - Grocott-Gomori): deposits in fungal cell wall - very sensitive; gold standard
  • Calcofluor white stain: fluorescent; useful
  • H&E: shows fungal cytoplasm; less sensitive
  • Gram stain: less useful

• Non-septate, wide-angle branching hyphae = Mucorales (mucormycosis)
• Septate, acute-angle branching hyphae = Aspergillus
• Angioinvasion or perineural invasion = pathognomonic

• CT paranasal sinuses: mucosal thickening, bony erosion, opacification; may be normal early
• MRI: better soft tissue; orbital/intracranial extension; bone marrow signal changes in skull base
• Note: normal CT does not exclude AIFS in high-risk patient

Management

1. Aggressive antifungal therapy (initiated immediately):
   • Liposomal amphotericin B (AmBisome): first-line for mucormycosis; 3-10 mg/kg/day IV; improved outcome vs. conventional amphotericin
   • Voriconazole: first-line for invasive Aspergillus AIFS
   • Isavuconazole: emerging broad-spectrum option
   • Duration: until immunosuppression reverses and clinical/radiological resolution
2. Surgical debridement (endoscopic/open): urgent, aggressive; remove all necrotic tissue; serial debridements often required
3. Reversal of immunosuppression:
   • Correct DKA urgently
   • Reduce/stop immunosuppressive agents if possible
   • Granulocyte transfusions in severe neutropenia
4. Hyperbaric oxygen: adjuvant; enhances neutrophil killing

Prognosis

• Mortality remains ~50% (largest systematic review) despite treatment
• Negative prognosticators: advanced age, palatal/facial necrosis, severe neutropenia (<500/μL), elevated CRP (≥5.50 mg/dL), altered mental status, renal/liver failure, intracranial extension
• Positive prognosticators: reversible immunosuppression (DKA), complete surgical resection, liposomal amphotericin B treatment

Differential Diagnosis

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8. JUVENILE NASOPHARYNGEAL ANGIOFIBROMA (JNA)

Definition

Epidemiology

• Age: 9-19 years (adolescent males); peak 14-17 years
• Sex: almost exclusively male (androgen-dependent)
• Incidence: 1 in 150,000; commonest benign nasopharyngeal tumor in adolescent males
• Rare reports in females
• Higher incidence in South Asian and African populations

Etiology / Pathogenesis

• Exact origin debated; epicenter at the pterygopalatine fossa (sphenopalatine foramen / base of pterygoid process / superior choana region)
• Schick's branchial artery theory: JNA develops from incomplete regression of the first branchial arch artery (formed days 22-24 in embryogenesis); vascular remnants → JNA; supported by finding that JNA vessels express laminin α2 (marker of early angiogenesis)
• Hormonal: androgen receptor overexpression in tumor; testosterone stimulates vascular channel muscularization; puberty triggers growth; tumor may regress post-puberty
• Molecular: upregulation of VEGF-A and FGFR pathway; β-catenin protein overexpression (Wnt signaling); molecular heterogeneity worldwide
• Histology: vascular spaces lined by endothelium (no smooth muscle layer); fibrous stroma with stellate/spindle cells

Spread Patterns

• Medially: through sphenopalatine foramen → nasopharynx and nasal cavity
• Laterally: through pterygomaxillary fissure → infratemporal fossa
• Anteriorly: pushes posterior wall of maxillary sinus forward (Holman-Miller sign on lateral X-ray/CT)
• Superiorly: along vidian canal → floor of sphenoid sinus
• Intracranially: through orbit, superior orbital fissure, or direct erosion of skull base

Staging (Andrews' modified classification, commonly used)

Clinical Features

• Epistaxis: recurrent, severe, often profuse; most common presenting symptom
• Nasal obstruction: unilateral progressive (tumor in nasal cavity)
• Nasal discharge
• Rhinolalia clausa (hyponasal speech)
• Anosmia
• Facial swelling: if infratemporal fossa involved (cheek swelling)
• Proptosis/diplopia: orbital extension
• Middle ear effusion (Eustachian tube compression): conductive HL
• Cranial nerve palsies: advanced disease
• Anaemia from chronic epistaxis

Investigations

• Biopsy: CONTRAINDICATED in office due to risk of catastrophic haemorrhage; biopsy only in operative setting
• CT paranasal sinuses + nasopharynx with contrast:
  • Lesion in pterygopalatine fossa
  • Holman-Miller sign (antral sign): anterior bowing of posterior wall of maxillary sinus on lateral projection
  • Bone erosion/remodeling
• MRI with contrast: defines soft tissue extent; differentiates tumor from retained secretions; shows intracranial extension; patchy/diffuse enhancement
• DSA (Digital Subtraction Angiography): pre-embolization; shows enlarged intratumoral vessels + intense inhomogeneous venous phase blush; defines blood supply (ECA branches: internal maxillary artery, ascending pharyngeal artery; ICA if intracranial extension)
• Testosterone levels: not diagnostic

Management

• Multiple approaches based on staging: endoscopic (preferred for Stage I-IIa), infratemporal fossa approach, Le Fort I osteotomy, facial translocation

• Performed 24-48 hours before surgery
• Transarterial particles (PVA) or liquid embolic agents (NBCA, Onyx)
• Direct tumor puncture with Onyx: improves devascularization
• Goal: reduce intraoperative blood loss and improve surgical access
• Risk: neurological deficit if ICA supply present
• Some advocate omitting embolization for smaller Stage I-II tumors (endoscopic resection without embolization now feasible)

• Reserved for intracranial extension, unresectable tumors, or recurrence
• Risk of radiation-induced malignancy in young patients

• Occurs in 6-24%; most within 2 years
• Serial MRI follow-up mandatory

Complications

• Profuse intraoperative hemorrhage
• Recurrence
• Radiation-induced second malignancy
• Intracranial extension (advanced untreated disease)
• Facial nerve damage (surgical)

Differential Diagnosis

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9. NASOPHARYNGEAL CARCINOMA (NPC)

Definition

Epidemiology

• Geography: endemic in Southern China (Cantonese population), Southeast Asia, North Africa, Inuit populations
• In endemic areas: most common cancer in men; 25-50/100,000/year
• Non-endemic (West): <1% of all cancers
• Age: bimodal peak - 15-25 years AND 50-60 years
• Sex: Male > Female (2-3:1)

Etiology / Pathogenesis

• Present in virtually all non-keratinizing and undifferentiated NPC
• EBV genome + EBV proteins (including LMP1 - Latent Membrane Protein 1) expressed in tumor cells
• LMP1 activates NF-κB pathway → oncogenic signals → epithelial transformation
• EBV infects nasopharyngeal epithelium; susceptible individuals (genetic predisposition) undergo transformation
• EBV anti-VCA IgA: sensitive diagnostic/screening marker

• HLA-A2 and HLA-B alleles associated with increased susceptibility
• Chromosome 3p, 9p, 11q, 13q, 14q deletions in NPC

• Salted fish (nitrosamines): particularly consumption in childhood
• Smoking, formaldehyde, wood dust exposure
• Preserved/fermented foods

WHO Classification (Histological Types)

Clinical Features

• Nasal obstruction (unilateral)
• Epistaxis
• Eustachian tube dysfunction → unilateral middle ear effusion (serous otitis media) with conductive HL in adult = NPC until proven otherwise

• Most common presentation: painless cervical lymphadenopathy (posterior triangle, upper deep cervical)
• Present in 70-90% at diagnosis
• Often bilateral

• CN VI palsy (diplopia) - most common
• CN V (facial numbness)
• CN IX/X/XI/XII (jugular foramen syndrome)
• Horner's syndrome

Investigations

• Nasoendoscopy + biopsy: direct visualization of fossa of Rosenmüller; biopsy to confirm histology
• MRI nasopharynx + neck: gold standard for primary tumor extent and nodal disease
• EBV serology: anti-VCA IgA (sensitive screening marker); EBV DNA in plasma (correlates with tumor burden and response)
• CT chest/abdomen/pelvis or PET-CT: distant metastasis staging
• Audiometry: if middle ear effusion
• TNM staging: AJCC/UICC 8th edition

TNM Staging (simplified)

• T1-T2: confined to nasopharynx, extending to oropharynx/nasal cavity (T2), no parapharyngeal extension
• T3: bony skull base or paranasal sinuses
• T4: intracranial extension, cranial nerve involvement, hypopharynx, orbit
• N: cervical nodes by size and location
• M: distant metastases

Management

• Definitive radiotherapy (RT) alone: external beam RT / IMRT (intensity-modulated radiation therapy) to 70 Gy
• Local control: 64-95% for T1-T2

• Concurrent chemoradiotherapy (CRT): cisplatin-based chemotherapy + IMRT
• IMRT: preferred technique; reduces xerostomia; spares parotids; 70 Gy to gross tumor volume
• 5-year OS: 36-58% overall; better with IMRT
• Distant metastases remain high (~30% in IMRT series)

• Immune checkpoint inhibitors (anti-PD-1: pembrolizumab, nivolumab): responses reported for recurrent/metastatic NPC; new therapeutic strategy

• Better conformality around critical structures (chiasm, brainstem)
• Parotid sparing (mean dose <26 Gy) → reduced xerostomia
• Improved loco-regional control (90% at 2 years)

Complications

• Xerostomia (radiation salivary gland damage)
• Temporal lobe necrosis
• Trismus
• Hypothyroidism (neck radiation)
• Cranial nerve damage
• Osteoradionecrosis
• Second primary malignancy (radiation)

Differential Diagnosis

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10. OBSTRUCTIVE SLEEP APNEA (OSA)

Definition

Severity Classification (AHI)

Epidemiology

• Prevalence: ~15-30% of males, 5-15% of females (using AHI ≥5 + symptoms criterion)
• Most common in middle-aged overweight males
• Increases with age; postmenopausal women approach male rates
• Significant underdiagnosis in clinical practice

Etiology / Predisposing Factors

Pathogenesis

1. Normal sleep → decreased activity of upper airway dilator muscles (genioglossus, tensor palatini)
2. Pharyngeal lumen narrows (anatomically small airway + muscle hypotonia during REM)
3. Critical closing pressure (Pcrit) concept: if Pcrit > atmospheric pressure → complete obstruction (apnea)
4. Fluid shift theory: rostral fluid shift (from legs to neck) in supine position increases neck circumference → pharyngeal narrowing

• Arousal: hypoxemia and hypercapnia → arousal → airway opens → resaturation → sleep resumes → cycle repeats
• Sleep fragmentation → non-restorative sleep → daytime sleepiness
• Intermittent hypoxia → oxidative stress, endothelial dysfunction
• Sympathetic activation → hypertension (nocturnal non-dipping pattern)
• Increased cortisol, inflammatory cytokines (IL-6, TNF-α, CRP)

Clinical Features

• Loud snoring
• Witnessed apneas (bed partner report)
• Choking/gasping episodes
• Restless sleep; frequent awakenings
• Nocturia (atrial natriuretic peptide release)
• Diaphoresis

• Excessive daytime sleepiness (EDS): cardinal symptom; Epworth Sleepiness Scale (ESS) ≥10
• Unrefreshing sleep
• Morning headache (CO2 retention)
• Cognitive impairment, poor concentration, memory difficulties
• Mood disturbance (depression, irritability)
• Decreased libido
• Road traffic accidents (drowsy driving)

• BMI >30 kg/m² (obesity)
• Neck circumference: >43 cm (male), >38 cm (female)
• Retrognathia, micrognathia
• Tonsillar/adenoid hypertrophy (especially children)
• Mallampati score III/IV (crowded oropharynx)
• Hypertension

Investigations

• Epworth Sleepiness Scale (ESS): ≥10 = excessive daytime sleepiness
• STOP-BANG score: Snoring, Tiredness, Observed apneas, blood Pressure, BMI, Age, Neck circumference, Gender; ≥3 = high risk

• Level 1: In-laboratory Polysomnography (PSG): gold standard; measures AHI, oxygen saturation, EEG (sleep staging), EMG, airflow, respiratory effort
• Level 3: Home Sleep Apnea Testing (HSAT): unattended portable device; appropriate for uncomplicated moderate-severe suspected OSA; measures AHI (as RDI)

• Blood tests: thyroid function (hypothyroidism), FBC (polycythemia)
• Lateral cephalometry/nasopharyngoscopy: anatomical assessment
• Arterial blood gas: hypercapnia (severe/obesity hypoventilation)

Management

• Weight loss: strongly recommended by ATS/AHA for all obese OSA patients; dietary + exercise; bariatric surgery for morbid obesity
• Positional therapy: avoid supine sleep (lateral positioning devices)
• Avoid alcohol and sedatives (especially near bedtime)
• Smoking cessation
• Sleep hygiene

• First-line treatment for moderate-severe OSA; pneumatic splint for upper airway
• Immediate effect; most efficacious for reducing AHI
• Improves EDS, cardiovascular risk, quality of life
• Limitation: adherence (~50% long-term)
• CPAP titration: manual in lab or auto-PAP (APAP) at home

• Advances mandible 60-70% of maximum protrusion during sleep
• Appropriate for mild-moderate OSA; CPAP-intolerant patients
• 3-month timeline for fabrication/adjustment
• Requires intact dentition

• Uvulopalatopharyngoplasty (UPPP): resects uvula, posterior soft palate, tonsillar pillars; moderate success
• Tonsillectomy + adenoidectomy: highly effective for children with OSA from tonsillar/adenoid hypertrophy
• Maxillomandibular advancement (MMA): most effective surgical procedure; advances midface and mandible; reserved for surgical failures
• Hypoglossal nerve stimulation (Inspire): for CPAP-intolerant patients; senses breathing effort → stimulates CN XII → tongue protrusion
• DISE (Drug-Induced Sleep Endoscopy): guides surgical site selection
• Bariatric surgery: for morbidly obese patients

Complications (Pathophysiology of Consequences)

Differential Diagnosis

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11. CHOLESTEATOMA

Definition

Classification

• Pars flaccida (attic) cholesteatoma: most common; begins as attic retraction
• Pars tensa (posterosuperior) cholesteatoma: begins as posterosuperior retraction
• Sinus cholesteatoma: extends into facial recess/sinus tympani
• Tensa cholesteatoma: through pars tensa perforation

Pathogenesis

1. Eustachian tube dysfunction (e.g., cleft palate, chronic OME) → chronic negative middle ear pressure
2. TM retraction (pars flaccida/posterosuperior pars tensa → attic retraction pocket)
3. Self-cleansing failure of retraction pocket → keratin accumulates
4. Epithelial invasion/migration into middle ear → "retraction pocket cholesteatoma"

• Osteoclastic activity driven by cytokines: TNF-α, IL-1α, IL-6 (expressed in cholesteatoma)
• Pressure necrosis
• Enzymatic degradation (matrix metalloproteinases)
• Pseudomonas aeruginosa LPS activates RANKL-primed osteoclasts via autocrine/paracrine cytokine mechanism

Clinical Features

• Foul-smelling otorrhoea (chronic, recurrent; becomes worse during URTI)
• Hearing loss (conductive initially; mixed if cochlear erosion)
• Aural fullness
• Otalgia
• Complications: facial palsy, vertigo, headache, meningism

• Attic perforation (marginal) with keratin/white debris
• Posterosuperior marginal perforation with cholesteatoma visible
• Intact TM with white mass behind it (congenital)
• Evidence of bone erosion (scutum erosion)
• Granulation tissue / polyp through perforation

• Facial nerve palsy
• Fistula sign (Hennebert's sign if labyrinthine fistula)
• Cerebellar signs (labyrinthitis/intracranial extension)

Investigations

• Otoscopy/microotoscopy: essential
• Audiometry: CHL or mixed HL; speech discrimination preserved initially
• CT temporal bone (HRCT): gold standard for extent; shows bony erosion of scutum, ossicular chain, tegmen, facial canal, semicircular canal
• Non-echo-planar Diffusion-Weighted MRI (DW-MRI): detects residual cholesteatoma (as small as 3 mm) without requiring second-look surgery; used for post-operative surveillance
• Culture of discharge: directs topical antibiotic therapy pre-operatively

Management

1. Safe ear (eradicate disease, prevent complications)
2. Dry ear
3. Hearing restoration (tympanoplasty/ossiculoplasty if possible)

• Ear toilet (microsuction)
• Topical antibiotics (ciprofloxacin drops) to dry active discharge

Complications

• Ossicular erosion → conductive HL (long process of incus most commonly affected, then stapes crura, then body of incus, then manubrium)
• Labyrinthine fistula (most commonly lateral semicircular canal) → vertigo + SNHL
• Facial nerve palsy (dehiscent facial canal erosion)
• Mastoiditis
• Petrous apicitis
• Tegmen erosion → CSF leak

• Meningitis (most common intracranial complication)
• Extradural abscess
• Subdural empyema
• Brain abscess (temporal lobe or cerebellum)
• Lateral sinus thrombosis
• Otitic hydrocephalus

Differential Diagnosis

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12. CSOM (CHRONIC SUPPURATIVE OTITIS MEDIA)

Definition

1. Inactive squamous epithelial COM: retraction, atelectasis, epidermization (no perforation, no discharge)
2. Active mucosal COM = CSOM: central TM perforation + otorrhoea + mucosal disease
3. Active squamous epithelial COM = Cholesteatoma: marginal perforation + keratin matrix

Etiology

• Pseudomonas aeruginosa: most common; responsible for persistent and recurrent discharge
• Staphylococcus aureus (including MRSA)
• Proteus mirabilis
• Escherichia coli, Klebsiella, anaerobes
• Mixed aerobic/anaerobic organisms common
• Fungal superinfection (Aspergillus, Candida) in topical antibiotic-treated ears

• Eustachian tube dysfunction (childhood otitis media, cleft palate)
• Recurrent acute otitis media → TM perforation
• Poor socioeconomic conditions, overcrowding, malnutrition
• Immunodeficiency

Pathology (Scott-Brown's Vol 2)

• Mucosal changes: chronic inflammation of middle ear and mastoid mucosa with:
  • Submucosal edema
  • Submucosal fibrosis
  • Hypervascularity
  • Inflammatory infiltrate: lymphocytes, plasma cells, histiocytes
  • Increase in goblet cells + basal cell hyperplasia
  • Granulation tissue (clinically = "aural polyps" protruding through perforation)
• Ossicular chain: long process of incus most commonly eroded (decreasing order: long process incus → stapes crura → body of incus → manubrium)
• Bone destruction: osteoclast activity stimulated by RANK/RANKL; TNF-α, IL-1α, IL-6 cytokines
• Pseudomonas LPS → RANKL-primed osteoclasts → bone resorption

Classification of Perforation

Clinical Features

• Chronic otorrhoea: persistent, foul-smelling, mucoid/mucopurulent; intermittent or continuous; exacerbated by URTI or water entry
• Tympanic membrane perforation: central/subtotal/total (pars tensa)
• Hearing loss: conductive; proportional to perforation size + ossicular status
• Tinnitus
• Mild discomfort; severe pain suggests complication
• No cholesteatoma (distinguishes from active squamous COM)
• Granulation tissue / polyp through perforation in active disease

Investigations

• Otomicroscopy: assess perforation, discharge, middle ear mucosa
• Audiometry: degree of CHL; air-bone gap; speech discrimination
• Tympanometry: flat (type B) or non-obtainable
• High-resolution CT (HRCT) temporal bone: assess mastoid, ossicular chain, tegmen, facial canal integrity; exclude cholesteatoma
• Swab and culture: from middle ear discharge (deep swab) to guide topical therapy
• Nasal endoscopy: assess Eustachian tube, adenoids
• Immunological workup (if recurrent/bilateral)

Management

1. Aural toilet (microsuction): remove discharge, debris; crucial for antibiotic effectiveness
2. Topical antibiotics (with/without steroids):
   • Ciprofloxacin drops (0.3%): first-line; excellent coverage for Pseudomonas; not ototoxic
   • Aminoglycoside drops (gentamicin, neomycin): effective but POTENTIALLY OTOTOXIC - avoid if oval/round window exposed
   • Topical steroid-antibiotic combinations
3. Oral antibiotics: systemic for exacerbations; directed by culture; ciprofloxacin for Pseudomonas
4. Keep ear dry: water precautions (cotton + petroleum jelly; custom mould; avoid swimming)
5. Treat nasal disease: manage chronic rhinosinusitis, adenoids, allergic rhinitis

• Tympanoplasty (myringoplasty): repair of TM perforation
  • Underlay technique (temporalis fascia graft, most common) or overlay technique
  • Prerequisites for surgery: dry ear for at least 3 months; no active infection; adequate ventilatory function of ET
  • Success rate: 80-95% for central perforations
• Tympanomastoidectomy: if mastoid disease/granulation; combined with tympanoplasty
• Ossiculoplasty: if ossicular erosion causing significant CHL; TORP or PORP prostheses

Complications

• Ossicular chain erosion → progressive CHL
• Labyrinthitis (bacterial or toxic) → SNHL, vertigo
• Facial nerve palsy (dehiscence of facial canal + infection)
• Mastoiditis with subperiosteal abscess
• Petrositis (Gradenigo's syndrome: CN VI palsy + retroorbital pain + ipsilateral otorrhoea)

• Meningitis (most common intracranial complication)
• Extradural abscess
• Brain abscess (temporal lobe or cerebellum)
• Subdural empyema
• Sigmoid/lateral sinus thrombosis
• Otitic hydrocephalus

Differential Diagnosis

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13. BPPV (BENIGN PAROXYSMAL POSITIONAL VERTIGO)

Definition

Types / Classification

Etiology / Pathogenesis

• Idiopathic: most common (~50-70%)
• Head trauma: 17% (Baloh et al.) - onset within days/weeks after trauma
• Presumed viral neurolabyrinthitis: 15%
• Osteoporosis: epidemiological association (Jeong et al.); calcium metabolism
• Post-Ménière's disease: degeneration of otolithic membrane
• Inner ear surgery
• Prolonged bed rest (particularly the affected side down)
• Vascular insufficiency of labyrinth

1. Otoconia (calcium carbonate crystals, normally embedded in otolithic membrane of utricle) detach from utricular macula
2. Particles gravitate into the posterior SCC (most common - lowest position in supine/head-hanging)
3. Head movement → particles move through the canal → endolymph displacement → cupula deflection → hair cell stimulation
4. Ampullofugal flow in the posterior canal = excitatory → upbeating geotropic-torsional nystagmus
5. Ewald's laws govern direction: eye movement plane = canal plane; horizontal canal: ampullopetal = excitatory; vertical canals: ampullofugal = excitatory

Clinical Features

• Paroxysmal vertigo: brief (typically <30-40 seconds, usually <15 seconds)
• Triggered by: lying down, rolling over in bed, looking up (head extension), bending forward, rising from bed
• Latency: 2-5 seconds after provocative position
• Fatigability: nystagmus/vertigo diminishes with repeated testing
• No hearing loss (distinguishes from Ménière's, labyrinthitis)
• No tinnitus (unless coincidental)
• Nausea; may vomit during severe attacks
• Normal neurological examination (no focal signs)
• Individual episodes last <1 minute
• May persist days to months to years; often spontaneously remits

Diagnosis - Bedside Testing

1. Patient seated with legs along examination couch
2. Head turned 45° toward the ear being tested (aligns posterior canal with sagittal plane)
3. Patient brought briskly to supine/head-hanging position with neck 30-40° below horizontal (over end of table), maintaining 45° head rotation
4. Observe for nystagmus and ask about vertigo
5. Positive test (posterior canal BPPV): after 2-5 second latency:
   • Upbeating + torsional nystagmus (fast phase toward dependent/affected ear)
   • Vertigo (patient may grasp table, become frightened)
   • Latency present; fatigable; reverses on sitting up
6. Dysfunctional ear = dependent (downward) ear when vertigo is elicited
7. Repeat → fatigue = strong sign of labyrinthine origin

• Patient supine; head turned 90° to each side
• Geotropic horizontal nystagmus (toward ground) = canalolithiasis
• Apogeotropic horizontal nystagmus (away from ground) = cupulolithiasis
• Side with stronger nystagmus = affected side (canalolithiasis)

Management

1. Dix-Hallpike position right (head 45° right, neck extended) - wait for nystagmus to stop
2. Head rolled 90° to left (nose pointing left, neck still extended)
3. Body + head roll further 90° left (patient lying on left side, nose pointing down)
4. Patient brought to sitting; head tilted down 30°
5. Wait 30 seconds at each position

• Vestibular suppressants (meclizine, dimenhydrinate, benzodiazepines): mask symptoms; do NOT treat cause; short-term use only for severe nausea
• Antiemetics (ondansetron, promethazine): nausea control

• Posterior canal occlusion: plugging the posterior semicircular canal; highly effective for refractory PC-BPPV; risk of permanent SNHL
• Singular neurectomy: sectioning the posterior ampullary nerve; difficult, rarely performed

• Most cases resolve spontaneously within weeks to months
• Elderly: may recur periodically for years
• Annual recurrence rate: ~15-30%

Complications

• Falls/injury during acute attacks (especially elderly)
• Recurrence (common)
• Quality of life impairment
• Rare permanent SNHL (from posterior canal occlusion surgery)
• Psychological distress

Differential Diagnosis

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QUICK REFERENCE SUMMARY TABLE

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• Scott-Brown's Otorhinolaryngology Head & Neck Surgery, Vols 1 & 2 (9781138094611 & 9781138094634)
• Cummings Otolaryngology Head and Neck Surgery (9780323612173)
• K.J. Lee's Essential Otolaryngology (9781260122237)
• Shambaugh Surgery of the Ear (9781607950264)
• Adams & Victor's Principles of Neurology, 12th ed (9781264264520)
• Robbins & Kumar Pathologic Basis of Disease (9780443264528 & 9780323790185)
• Murray & Nadel's Textbook of Respiratory Medicine (9780323655873)
• Robbins & Kumar Basic Pathology (9780323790185)