Basal cell adenocarcinomas of the major salivary glands.

Basal cell adenoma of salivary gland has become an established variant of monomorphic adenoma since its segregation from pleomorphic adenoma in 1967. Although there have been many comprehensive reports about benign basal cell adenomas, only rare case reports of malignant basal cell type neoplasms have appeared in the literature. Described in this report are the clinicopathologic features of 29 cases labeled basal cell adenocarcinomas that had morphologic characteristics of basal cell adenomas but infiltrative, perineural, and intravascular growth features that indicated a malignant potential. With limited follow-up, seven tumors are known to have recurred, and three of these metastasized to lymph nodes and lung. One patient died with extensive local spread of the tumor. All patients were adults. The peak incidence was in the sixth decade of life, and there was no gender predilection. The parotid gland was the predominant site. A solid type growth configuration was most frequent; membranous, trabecular, and tubular types were less frequent, in that order. Three patients also had dermal cylindromas, perhaps indicative of a salivary gland-skin adnexal diathesis that has been previously reported.