Carcinoma in-situ of the Oral Mucosa has a Definite Tendency towards Keratinization.

Abstract

A 81-year-old female had suffered from a white lesion in the right lateral margin of the tongue for 10 years. The lesions was surgically removed and examined histopathologically. The surgical specimen showed small foci of squamous cell carcinoma invading up to 4 mm in the muscle layer with a diameter of less than 7 mm in the central portion. The carcinomatous foci were surrounded by epithelial dysplasia in various degrees with a dense lymphocytic infiltration in the lamina propriae. Some of the dysplasia parts just next to the carcinomatous foci contained obviously atypical cells without basal cell alignment but with an apparent keratinizing tendency, which could not be otherwise diagnosed as carcinoma in-situ. Based on this case report, a new concept of carcinoma in-situ of the oral mucosa was proposed, because the histology was different in terms of keratinization degree from so-called carcinoma in-situ as frequently seen in the cervix uteri, which were mainly composed of proliferation of basaloid cells.