What Is Your Diagnosis? Anal Mucosal Melanoma

A 67-year-old man presented to his primary care physician with a pink nodule on the perianal skin of 2 years’ duration. This lesion initially had been treated with liquid nitrogen and remained asymptomatic for 1.5 years. Several months prior to presentation he noted blood-stained undergarments. There was no pain with this incident. The patient’s medical history included a thin truncal melanoma, coronary artery disease, hypercholesterolemia, and hypertension.