Tumors of nasal passages, nasopharynx and larynx

A) Tumors of Nasal Passages

• Squamous cell carcinoma: most frequent malignant nasal tumor
• Adenocarcinoma: glandular origin; 2nd most common of nasal cavity/paranasal sinuses
• Malignant melanoma: from melanocytes; aggressive; only ~1% of tumors in this area
• Inverting papilloma: benign wart-like growth; may develop into squamous cell carcinoma
• Esthesioneuroblastoma: rare; originates from neuroectodermal olfactory cells; must distinguish from neuroendocrine cancer
• Midline granuloma: midfacial necrotizing lesion; destructive mucosal lesions of upper aerodigestive tract
• Lymphoma, Sarcoma

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B) Nasopharyngeal Carcinoma

Epidemiology

• Most common cancer originating in the nasopharynx
• High frequency in China and Africa; rare in the US
• Africa → most common childhood cancer (associated with EBV)
• South China → most common cancer in male adults

Pathogenesis

• Associated with EBV infection
• EBV first replicates in nasopharyngeal epithelium → infects nearby B-cells of tonsils → in some, leads to epithelial cell transformation

Morphology

• Histology: squamous cell carcinoma (transformed epithelial cells)
• Three histological subtypes:
  1. Well differentiated keratinizing squamous carcinoma
  2. Moderately differentiated non-keratinizing squamous carcinoma
  3. Undifferentiated carcinoma: most common; most strongly associated with EBV; large epithelial cells with indistinct borders (“syncytial” growth) + prominent eosinophilic nucleoli

Clinical

• Local invasion → spread to cervical lymph nodes → distant metastases
• Therapy: immunotherapy (interferon), radiotherapy, chemotherapy

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C) Laryngeal Tumors

Non-Malignant Lesions

1. Vocal cord nodules (“polyps”)

• Smooth, hemispherical protruding masses on the true vocal cords
• Composed of fibrous tissue; covered by stratified squamous epithelium (may be ulcerated by contact trauma)
• Occur in heavy smokers or singers (“singer’s nodules”) → response to chronic irritation
• Not a benign proliferation — a non-inflammatory response to injury/irritation

2. Laryngeal papilloma

• Squamous papilloma of the larynx; benign neoplasm on true vocal cords
• Histology: finger-like projections with central fibrovascular core; covered by stratified squamous epithelium
• Trauma → ulceration → hemoptysis
• Children: usually multiple; do not become malignant; often spontaneously regress at puberty; HPV 6 and 11; vertical transmission from mother
• Adults: usually solitary; more in men; recurrences frequently show dysplasia

Malignant Lesions

Laryngeal carcinoma

• Age >40; more common in men
• Risk factors: smoking, heavy alcohol consumption, asbestos exposure
• Most are squamous cell carcinomas
• Growth: in situ → grey wrinkled plaques → ulcerated + necrotized

Location and prognosis:

Location	Site	Prognosis	Notes
Glottic	On vocal cords	Best (early symptoms; poor lymphatic supply)	Most common; keratinizing, moderately differentiated
Supraglottic	Above vocal cords	Intermediate	Rich lymphatics; 1/3 metastasize to cervical LN
Subglottic	Below vocal cords	Worst (no early symptoms; rich lymphatics)	Less common

• Metastases: regional lymph nodes + lungs; direct extension to thyroid gland, jugular vein
• Therapy: surgery, radiation, or combined
• ~1/3 of patients die from distal respiratory infection, metastases, or cachexia

💡 High-yield: Nasopharyngeal carcinoma = EBV; undifferentiated type most common + most EBV-associated; China/Africa. Vocal cord nodules = smokers/singers; NOT a neoplasm. Laryngeal papilloma = HPV 6+11; children = multiple, regress at puberty. Laryngeal carcinoma = SCC; glottic = best prognosis; subglottic = worst.