Nasopharyngeal carcinoma. A “different” head and neck tumour. Part A: from histology to staging

As in some other sites of the head and neck, a broad range of tumours can arise in the nasopharynx: epithelial, mesenchymal, lymphoid, and neuro-ectodermal. However, nasopharyngeal carcinoma (NPC) is the most interesting and intriguing type, because it is a “peculiar” malignancy, and “different” from almost all other head and neck tumours according to several points of view. In fact, NPC is a unique disease whose aetiology, clinical behaviour, epidemiology, and histopathology are different from those of all other squamous cell carcinomas of the head and neck. The most distinguishing characteristics of this malignancy are the consistent association with Epstein-Barr virus and the striking geographical differences in its incidence. The aim of this narrative review is to analyse the very large number of studies (sometimes contradictory) on NPC. In this first part, the histopathology, aetiology, epidemiology, clinical behaviour, natural history, diagnostic work up, and staging will be examined.