Presentation and methods of spread

Unilateral deafness, secondary to Eustachian tube blockage, is the most common local symptom, followed by epistaxis. Nasal obstruction is common when the tumour is advanced. NPC spreads into the parapharyngeal space laterally, anteriorly to the orbit and paranasal sinuses, inferiorly to the oropharynx, and superiorly through the base of the skull. Any of the cranial nerves can be involved by the tumour. In practice, the Vth nerve is involved most frequently owing to tumour in or around the foramen ovale. Tumour in the cavernous sinus can lead to diplopia secondary to compression of the IV, III, or VI nerves. The posterior cranial nerves (IX to XII) can be involved by direct parapharyngeal spread or compression by retropharyngeal lymph nodes.

Cervical lymph node spread is common and is a frequent presentation. Bilateral or unilateral upper deep cervical nodes just below the mastoid are frequently involved. Caudal spread of nodal disease correlates with distant spread and this is the basis of the Ho staging scheme. Distant spread to bone (often with sclerotic metastases), the liver, and lung is common in advanced stage disease.

CT scanning of the base of the skull, nasopharynx and neck, thorax, and liver is an essential part of pre-treatment assessment. About a quarter of patients with low cervical or supraclavicular nodes have a positive isotope bone scan.

In the Far East, the Ho staging system is used instead of the UICC scheme. It is argued that it is often impossible to decide whether the tumour is confined to only one subsite and the UICC T staging does not correlate well with prognosis. The nodal staging system is particularly inappropriate as the tumour originates in the midline and bilateral spread is common. Nodal size or the degree of fixation are not important prognostic variables, but the level of nodal spread is related to the probability of distant spread.

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