Histologic examination of the biopsy specimen revealed epidermal atrophy, mild architectural disarray, and abrupt necrolysis of the upper stratum spinosum, with cytoplasmic eosinophilic homogenization and pyknotic nuclei. Papillary dermal edema and a mild inflammatory infiltrate of lymphocytes, histiocytes, mast cells, and extravasated red blood cells were noted. Direct immunofluorescence was negative for IgG, IgA, IgM, fibrin, C3, and IgG4. Based on the laboratory results and clinical and histological findings, a diagnosis of necrolytic migratory erythema and glucagonoma syndrome was suspected. The computed tomographic scan of the abdomen revealed a distal pancreatic tumor, confirming the skin diagnosis. A resection of the distal pancreas showed cords and nests of atypical islet cell tumor cells.