Lymphoepithelial carcinoma (Schmincke type) as a derivate of the tonsillar crypt epithelium.

Ten tumours of tonsillar or epipharyngeal localization showing the histological picture of "lymphoepithelial carcinoma" (Schmincke 1921) were examined immunohistochemically using Peanut lectin, Ulex europaeus lectin-I and an antiserum to S-100 protein. The findings suggest a close relationship of this type of carcinoma to the normal tonsillar crypt epithelium. The majority of tumour cells are UEA-I-positive and PNL-negative, as is the crypt epithelium, while oral mucosa is both PNL- and to a lesser extent UEA-I-reactive. Tumour areas expressing this pattern contain a large number of asteroid-shaped PNL-positive histiocytes and arachnoid-shaped histiocytes reacting with anti-S-100 protein; both cell types being probably identical and representing typical elements of the normal tonsillar crypt epithelium. Consequently, the WHO-term "nasopharyngeal carcinoma, undifferentiated type" seems to be inadequate for this type of tumour.