Basal cell carcinomas arising within multiple trichoepitheliomas.

Although trichoepitheliomas (TEs) are commonly regarded as benign tumors of follicular origin, the natural history of multiple familial trichoepitheliomas (MFT) and their risk for malignancy has been unclear. We describe a 57-year-old male with numerous skin-colored firm papules and plaques present on the central face since 6 years of age. Recently, some lesions had enlarged and ulcerated. Other family members were similarly affected. Biopsies from multiple lesions showed TEs both alone and associated with basal cell carcinoma (BCC) in the same section, suggesting the secondary development of BCCs within TEs. Many prior reports of BCCs arising within TEs in patients with presumed MFT were likely misdiagnosed cases of nevoid BCC. This report is a compelling example of MFT in which BCCs evolved secondarily. Awareness of the potential for the evolution of carcinoma in patients with MFT is important in the management of these patients.