THE CONGENITAL BASAL-CELL ADENOMA OF SALIVARY-GLANDS - CONTRIBUTION TO THE DIFFERENTIAL-DIAGNOSIS OF CONGENITAL SALIVARY-GLAND TUMORS

Congenital epithelial tumours of the salivary glands are very rare. Th e Salivary Gland Registry maintained in the Department of Pathology, U niversity of Hamburg, contains only three cases among a total of 6,646 salivary gland rumours from the years 1965-1994. The three cases were classified as congenital basal cell adenoma, two of the parotid gland and one of the submandibular gland. Histologically, the three adenoma s were similar in structure to the adult counterpart of basal cell ade noma with solid, trabecular or tubular (duct-like) patterns. In some c ystic spaces of the duct-like structures PAS- and Astra blue-positive substances were secreted. On immunocytochemistry, the luminal duct-lik e cells showed membranous expression of cytokeratins 3, 5, 6, 7, 13 an d 19. In the isomorphic basaloid cells of the solid and trabecular cel l nests few cells expressed cytokeratin. On the outside of the solid c ell nests there were smaller elongated myoepithelial-like cells, which expressed cytokeratin 14 and vimentin. Cytokeratins 1, 2, 4 and 18 we re not expressed. The pattern of expression reflects the different sta ges of maturity of the tumour cells and is related to the development of the salivary glands until the end of the 3rd embryonal month with a n arrest of further cell differentiation. No acinic cells, invasive gr owth, recurrence or metastases were observed. The differential diagnos is includes other congenital salivary gland tumours, such as hybrid ba sal cell adenoma-adenoid cystic carcinoma, sialoblastoma or embryoma, carcinoma, hamartoma and teratoma.