A Lesion on the Scalp

A 67-year-old man presented with a rapidly enlarging scalp lesion (Figure 1A) first noticed 3 months earlier as a pimple. The lesion was itchy but without generalized pruritus. The patient reported a weight loss of 10 pounds over the preceding 3 months. In addition, he reported a longer history of vague, nonspecific, intermittent abdominal pain without nausea, vomiting, or fever starting about 3 years prior to presentation. Previous work-up had revealed minimal abdominal adenopathy, but the patient declined further workup. On examination, he had no other cutaneous lesions, but he did have cervical lymphadenopathy. All other physical findings were within normal limits. Laboratory findings were unremarkable, save for a mild normochromic normocytic anemia and a mildly elevated levels of lactate dehydrogenase. A biopsy specimen from the skin lesion is shown in Figure 1B.