Microcystic adnexal carcinoma misdiagnosed as a "recurrent epidermal cyst": A case report.

Background: Microcystic adnexal carcinoma (MAC) is a rare malignant cutaneous adnexal neoplasm, often presenting as a flesh-colored and slow-growing indurated plaque or cystic nodule in the mid-facial region. Its characteristic indolent presentation usually leads to initial misdiagnosis, resulting in tumor mismanagement and added morbidity due to increased propensity for local invasion.

Case Summary: A 63-year-old Chinese male patient with a long-term history of excessive ultraviolet irradiation had received two surgeries for an "epidermal cyst" on his glabella and was presented to our hospital's Dermatology Department for further diagnosis and therapy of the lesion on his glabella.