Derm Dx: White lumps on the heel when standing

A 55-year-old man presents complaining of asymptomatic lumps on the sides of his heels that appear when he is standing up, but seem to disappear when sitting.

The patient has a history of gout, having experienced two gouty attacks in his left large toe in the past 20 years. He takes hydrochlorothiazide for hypertension. His father died of melanoma, and ...