Nasopharyngeal Pathology
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Direct answer
Undifferentiated carcinoma of the nasopharynx is the tumour that behaves like an infection and spreads like a cancer: Epstein-Barr virus-driven carcinoma arising in the lateral wall (fossa of Rosenmüller), presenting with a neck node rather than nasal complaints, serous otitis media from Eustachian obstruction, or cranial nerve palsies through the foramen lacerum. The WHO classifies it into keratinising squamous (type I), non-keratinising differentiated (type II) and undifferentiated (type III) carcinoma — types II and III are EBV-associated, radiotherapy-sensitive and dominate high-incidence populations. In India, the Northeast — Nagaland, Mizoram, Manipur — records incidence rates comparable to southern China among its Mongoloid-origin populations, a geography-plus-genetics story (HLA-linked susceptibility) that examiners from the region expect candidates to know.
What you must remember
- Anatomy decides presentation: the nasopharynx sits behind the nasal cavity, around the Eustachian cushions and fossa of Rosenmüller; tumours there cause blood-stained nasal discharge, unilateral secretory otitis media (blocked Eustachian tube) and nasal obstruction late.
- The neck node first: up to three-quarters of patients present with a cervical lymph node — classically a level V (posterior triangle) or upper deep cervical mass — because nasopharyngeal carcinoma metastasises early and bilaterally to retropharyngeal and cervical chains.
- WHO typing: type I keratinising squamous carcinoma (EBV-linked less consistently, radioresistant, worse local control); type II non-keratinising differentiated; type III undifferentinated carcinoma with lymphoepithelioma pattern — syncytial sheets of malignant epithelial cells densely infiltrated by lymphocytes (the old Schmincke-Regaud lymphoepithelioma).
- EBV markers: clonal episomal EBV DNA in the tumour cells, elevated IgA antibodies to viral capsid antigen and early antigen for screening and follow-up in endemic areas, and EBV-encoded small RNAs (EBER) on in-situ hybridisation as the diagnostic stain.
- Cranial nerve route: spread through the foramen lacerum to the cavernous sinus affects cranial nerves III, IV, V and VI — diplopia and facial numbness are ominous presenting features; the petrous apex adds VI palsy (Gradenigo-like picture).
- Geography and India: highest incidence in southern Chinese, Inuit and Southeast Asian populations; within India, Nagaland and neighbouring Northeast states carry rates of the same order, attributed to HLA-related genetic susceptibility plus preserved-fish and wood-smoke exposures interacting with EBV.
- Non-neoplastic conditions: adenoids (nasopharyngeal tonsillar hyperplasia) in children with snoring; Thornwaldt cyst from notochordal remnant; angiofibroma — see below.
A juvenile male with epistaxis, worked through
A 15-year-old boy has recurrent unilateral epistaxis and progressive nasal obstruction without cervical nodes: that combination in an adolescent male is juvenile nasopharyngeal angiofibroma, a benign but locally aggressive, hormone-sensitive tumour of vascular channels and fibrous stroma arising in the sphenopalatine foramen. The steps are characteristic — avoid biopsy (bleeding can be torrential); confirm with contrast computed tomography or angiography showing a vascular mass extending to the pterygopalatine fossa with Holman-Miller sign (anterior bowing of the posterior maxillary wall); embolise then resect. Contrast this with a 45-year-old Northeast Indian man with a level V neck node and a silent nasopharynx: here the biopsy comes from the nasopharynx itself or the node (EBER-positive undifferentiated carcinoma), staging includes magnetic resonance imaging of the skull base, and treatment is concurrent chemoradiotherapy with cisplatin — high cure rates in type III disease, and EBV DNA titres track response. Two masses, same site, opposite biopsy rules — a contrast examiners relish.
Where students slip
The reflex error is to approach every neck lump with fine-needle aspiration first and treat the nasopharynx as an afterthought; for an undiagnosed upper-neck or posterior-triangle node, the nasopharynx is part of the primary survey, especially in patients from high-incidence regions. Second, candidates misclassify the lymphoepithelioma as a lymphoma because the histology is sheeted with lymphocytes — the malignant cells are epithelial, cytokeratin-positive, EBER-positive, and lymphoma markers are negative; this immunohistochemistry panel is a standing viva question. Third, students forget that unilateral serous otitis media in an adult is nasopharyngeal carcinoma until scoped — the Eustachian catheter question is old, the principle is not.
Frequently asked questions
Which virus drives nasopharyngeal carcinoma and which antibody is followed?
Epstein-Barr virus; IgA antibodies to viral capsid antigen and early antigen are used for screening and monitoring, while EBER in-situ hybridisation confirms the diagnosis on tissue.
What are the WHO histological types?
Type I keratinising squamous carcinoma, type II non-keratinising differentiated carcinoma, and type III undifferentiated carcinoma with the lymphoepithelioma pattern.
Why does nasopharyngeal carcinoma present with a neck node?
The nasopharyngeal mucosa has rich lymphatic drainage to retropharyngeal and cervical chains, so ipsilateral and bilateral node metastases occur early, often before local symptoms.
Which tumour must never be biopsied transnasally?
Juvenile nasopharyngeal angiofibroma in adolescent males — a highly vascular tumour requiring imaging diagnosis, preoperative embolisation and surgical excision.
Why is nasopharyngeal carcinoma common in Northeast India?
Mongoloid-origin populations carry HLA-linked susceptibility, compounded by dietary and environmental exposures, yielding incidence rates comparable to southern China, particularly in Nagaland and Mizoram.