[Microcystic adnexal carcinoma of the skin. An underestimated tumor].

Microcystic adnexal carcinoma is a rare semimalignant cutaneous neoplasm characterised by slow but locally aggressive growth. Its histogenesis and nomenclature are still a subject of controversy. Under-recognition and the tumor's bland cytologic features lead to frequent misdiagnoses. In addition, subclinical tumour invasion explains the high incidence of local recurrence. Thus, the tumour makes great demands on the planning of its surgical removal. We report the case of an 81-year-old woman with a microcystic adnexal carcinoma of the lower lip, which was treated by micrographic surgery. On the basis of this case, differential diagnoses, histogenesis and micrographic surgery as the treatment of choice are discussed.