Carcinoma of the dorsum of the tongue: a rarity or misdiagnosis.

Benign lesions occurring on the dorsum of the tongue have at times been diagnosed as carcinoma. A retrospective investigation into the problem is described and the clinical and histological difficulties that arise in the diagnosis of these lesions are discussed. It is concluded that the occurrence of primary carcinoma on the dorsum of the tongue is a rare entity. It may be erroneously diagnosed in cases of median rhomboid glossitis, granular cell myoblastoma and any other lesion associated with pseudoepitheliomatous hyperplasia. These conditions should always be considered when examining lesions in this location. Histological diagnosis, although difficult, is greatly facilitated by good biopsy technique but, above all, good liaison between surgeon, radiotherapist and pathologist is essential if these mistakes in diagnosis are to be avoided.