Membranous basal cell adenoma of the parotid gland. Malignant transformation in a patient with multiple dermal cylindromas.

The rare association of dermal cylindroma (turban tumor), trichoepithelioma, eccrine spiradenoma, and membranous basal cell adenoma of the parotid gland has been previously reported. It is believed that this combination represents a peculiar inherited tumor diathesis involving neoplasms of presumed ductal origin, eccrine in the skin and intercalated in the parotid gland. We describe a patient in whom the basal cell adenoma of the parotid gland underwent malignant transformation.