Acral steatocystoma multiplex.

Steatocystoma multiplex (SM) is characterized by multiple, widespread cutaneous cystic lesions. These lesions can appear virtually anywhere on the body but are more common in areas where the pilosebaceous apparatus is well developed, such as the trunk (especially the presternal area), neck, axilla, inguinal region, scalp, and proximal extremities. We present a case of a woman with predominantly acrally located SM. To the best of our knowledge, a predominantly acral distribution has never been reported. We hypothesize that this patient's phenotype may be due to her genetic predisposition, possibly involving a familial defect in keratin 17, in combination with "ectopic" acral sebaceous follicles.