Basal cell adenocarcinoma of the palate with squamous metaplasia

Basal cell adenocarcinoma is a rare salivary gland tumour, especially in mi nor glands. The clinical, histological, and immunohistochemical features of a case involving the palate are described. Formalin fixed, paraffin embedd ed sections of the tumour were examined in haematoxylin and eosin (H&E) sec tions and also using immunostaining for cytokeratins 7, 8, 13, 14, 18, 19, vimentin, muscle specific actin (HHF35), and laminin. H&E sections showed t hat the tumour was composed mainly of basaloid cells and a striking feature was the presence or squamous metaplasia. Neural invasion was also conspicu ous. Immunohistochemical reactions indicated that cytokeratin 14 was expres sed by all tumour cells and vimentin by all cells except those in the areas of squamous metaplasia. The remaining cytokeratins and actin were present in some of the tumour cells, while laminin showed discreet positivity aroun d cell arrangements. The foci of squamous metaplasia and the immunohistoche mical findings are helpful in distinguishing basal cell adenocarcinoma from other salivary gland tumours which show basaloid cells.