[Case #4. Cutaneous cysts].

Cystic neoplasms are frequently observed on the skin. These can be classified into three categories: (1) malformative/dysembryoplastic cysts, (2) acquired cysts (constantly cystic tumors) of epidermal or folliculo-sebaceous differentiation, (3) acquired cysts of sweat differentiation, which must be distinguished from sweat tumors, sometimes harboring cystic changes. The aim of this session is to present the most frequent cystic lesions, those associated with a genetic syndrome (notably cancer predisposition syndromes), and malignant tumors that may simulate cysts.