Hidradenocarcinoma of the lower lip with squamoid differentiation: First reported case treated with Mohs micrographic surgery

Hidradenocarcinoma is a rare malignant adnexal ductal sweat gland tumor.1 It most commonly arises in middle-aged to older adults, with a median age of approximately 60 years.1 While most cases occur in the head and neck region, lip involvement is infrequently found.2 Mohs micrographic surgery (MMS) has attained favorable local control of hidradenocarcinoma, with a Mayo Clinic study of 10 patients reporting no recurrences after a mean follow-up of 7 years.3 We present a case of hidradenocarcinoma on the lower vermilion lip with dermoscopic findings.