Cutaneous masses, rib lesions, and chylous pleural effusion in a 20-year-old man.

A 20-year-old white man sought medical attention after noting the development of nontender masses in the left supraclavicular and left flank regions. There was no history of trauma, recent illness, prior similar masses, fever, chills, weight loss, or other symptoms. Past medical history was notable only for the excision of a “rib cyst” at age 12. He did not smoke, use alcohol or take any medications. On physical examination, two ill-defined subcutaneous soft mass lesions, one in the left supraclavicular fossa (4 x 5 cm) and a second in the left flank (6 x 6 cm) were identified. The lesions were nontender and