Flank ulcer in a patient with primary antiphospholipid syndrome.

A 32-year-old woman had a recurrent shallow ulcer on the flank. A biopsy specimen showed thromboses in the dermal vessels and she was found to have circulating antiphospholipid antibody with no associated systemic disease. A clean ulcer developed on the flank of a patient with primary antiphospholipid syndrome is considered to be a rarely encountered/unusual presentation of this syndrome.