A 24-year-old man was referred for evaluation and management of a large left abdominal wall mass. He had no other medical problems, no history of previous surgical procedures, and no previous abdominal wall trauma. The patient had a small spot on his abdominal wall at birth that had gradually increased; in the last year, the spot exhibited a significant increase, and the patient became alarmed when he started to experience chronic abdominal pain, constant constipation, and dysuria. A fine needle aspiration biopsy of the mass revealed evidence of small blood vessel proliferation in both the dermis and the subdermal adipose tissue. On examination there was a visible, palpable, nontender, 10 × 15-cm abdominal wall mass, with bluish skin discoloration.