Hair Repigmentation in Microcystic Adnexal Carcinoma

The document reports a case of hair repigmentation in a 74-year-old man with microcystic adnexal carcinoma (MAC) on the scalp. The patient presented with dark hairs surrounding a scar-like lesion, prompting further investigation. Histopathological analysis confirmed MAC, characterized by infiltrative strands and duct-like structures with perineural involvement. Immunostaining revealed melanocytes and melanin in some hair follicles, suggesting the tumor may stimulate melanin production. This is the first reported case of hair repigmentation associated with MAC, highlighting the need to consider malignancy in cases of spontaneous hair repigmentation. The patient underwent successful Mohs surgery to remove the tumor.