[Mandibular mucoepidermoid tumor].

One case of mandibular mucoepidermoid tumour was observed in a 57 years old man. A progressive swelling of the mandible was shown with an osteolytic feature on roentgenograms. It was treated by hemimandibulectomy. Grossly, the neoplasm was partly cystic. Histologically, it was mainly composed of intermediate clear cells. Its ultrastructure was quite similar to that of mucoepidermoid tumours in other sites. Heterotopic salivary lobules, though lacking in our case, seem to play the major role in the genesis of these tumours.