SQUAMOUS-CELL CARCINOMA OF THE TONSILLAR REGION AND THE BASE OF THE TONGUE - A MORPHOLOGICAL AND IMMUNOHISTOCHEMICAL COMPARATIVE PILOT-STUDY

Sixteen squamous cell carcinomas of the tonsillar region and 13 carcin omas of the base of the tongue were studied in a search for significan t differences between the tumours of these two oropharyngeal subsites, which are known to carry a significantly different prognosis. The cha racteristics of the tumour cells and the tumour-host relationship were scored on H & E-stained slides, as well as on slides stained with a p anel of antibodies. The results obtained were cross-tabulated and anal ysed with respect to the subsite. Ten variables were tested: cytonucle ar pleomorphism, mitotic activity, the presence of atypical mitoses, k eratinization, tumour grade, presence of eosinophils, severity of infl ammatory response, and the expression of keratin-10, blood group antig ens and collagen IV. When split up by site, only cytonuclear pleomorph ism revealed a significant difference, tonsillar carcinomas more often exhibiting marked pleomorphisni (p = 0.04). Despite having some progn ostic relevance for squamous cell carcinomas of the head and neck, the variables tested could not provide an explanation for the difference in biological behaviour of the tumours studied.