[Lymphoepithelial carcinoma of the oropharynx: incidence and differential di]

From 1960--1980, 452 malignant tumors of the oro- and nasopharynx were observed in the Cologne university ENT-clinic. 313 tumors of the oropharynx and 119 of the nasopharynx could be reclassified using the current classifications of upper respiratory tract tumors (WHO and Cologne modification) and of malignant lymphomas (German Kiel and Rappaport classifications). The analysis showed a different distribution of histological diagnoses in the naso- and oropharynx. Whereas the squamous cell carcinoma dominates with 57% in the oropharynx it is seldom seen (only 13%) in the nasopharynx. The non-keratinizing the undifferentiated carcinomas showed an inverse distribution in both regions. Malignant lymphomas and other types of malignant tumors occur equally frequent in the naso- and in the oropharynx. Only patients with non-keratinizing and undifferentiated carcinomas of the nasopharynx showed elevated antibody titers against Epstein-Barr virus. 7 patients with tumors of the same histological type but localization in the oropharynx had no elevated antibody titers against EBV.