A 46-year-old woman presented with a 4-month history of a slowly growing, 6-mm-diameter, ulcerated, violaceous nodule on the umbilicus (Figure 1). She complained of local tenderness and occasional bleeding that increased during her menstruation. She had no history of previous illnesses or abdominal surgery.
The lesion was excised, and the histopathologic features are shown in Figure 2.