Multifocal dermal-type basal cell adenomas of parotid glands with co-existing dermal cylindromas.

A basal cell adenoma of the parotid gland accompanied by multiple developing microadenomas of the same type and three dermal cylindromas, all observed in a 54-year-old woman, were examined by light microscopy. The histological structure of the basal cell adenomas shows striking similarities to co-existing dermal cylindromas, suggesting a common histogenesis of both tumors. We suggest that the term "basal cell adenoma of dermal type" should be used for these lesions. Multifocal ductal proliferations with nascent adenomas in the glandular parenchyma allow us to trace the development of these tumors. Studies of the literature reveal four additional cases in which there are co-existing basal cell adenomas of salivary glands and dermal adnexal tumors.