A man in his 40s presented with a 7-year history of a pruritic, annular cutaneous eruption and flaccid vesicles. The eruption was episodic in nature with spontaneous exacerbations and remissions. He reported modest weight loss but was otherwise well. Physical examination revealed crusted papules and polycyclic plaques with a map-like margin mainly involving the perioral region, chest, groin, buttocks, and extremities (Figure). His tongue appeared beefy red and his nails were brittle with transverse fissuring. A skin biopsy was performed and showed necrolysis in the upper third of the epidermis, vacuolation of the epidermal keratinocytes, and a superficial perivascular lymphocytic infiltrate. Laboratory analysis found a fasting blood glucose level of 6.5 mmol/L (normal range, 3.6 to 6.1 mmol/L) and a serum glucagon level of 1024 ng/L (normal range, 49 to 114 ng/L). The diagnoses of glucagonoma syndrome and associated necrolytic migratory erythema (NME) were made. A contrastenhanced abdominal computed tomographic scan revealed an enhancing pancreatic tail mass measuring 6.5 cm in maximum diameter. The patient underwent a subtotal pancreatectomy and splenectomy. Pathologic analysis confirmed a pancreatic neuroendocrine carcinoma consistent with a diagnosis of glucagonoma. Two weeks after the surgery, the patient's cutaneous lesions had nearly re-3.