An umbilical nodule with cyclical changes.

A 47 year old non-parous woman who had never had abdominal surgery was admitted with a four year history of an intermittently palpable nodule in the umbilical region. Initially, she noticed an increase in lesional size and pressure pain, which resolved within a few days. Six months before admission, blue-black discoloration appeared in the umbilical area; this vanishedwithin a week but reappeared cyclically, along with an increase in size of the nodule and localised discomfort. Macroscopic inspection during menstruation showed a sharply confined blue-black macule within the umbilical area. Lesional palpation identified a circumscribed, firm, well relocatable pea sized nodule just below the umbilical skin. Dermoscopy of the area showed features corresponding to a cutaneous haematoma. Questions