Necrolytic migratory erythema is a disorder highly suggestive of glucagonoma syndrome. We carried out histologic and electron microscopic studies of the skin lesions in a 57-year-old woman with the glucagonoma syndrome. Light microscopic studies revealed hyperkeratosis, parakeratosis, formation of clefts in the upper epidermis, and scattered dyskeratotic cells. Ultrastructurally, the intercellular spaces were widened in the upper epidermis and desmosomes were reduced in number. The cytoplasm of affected cells showed vacuolar degeneration; the organelles were lysed or absent. There were scattered dark cells and dyskeratotic cells. These changes appear to represent a degenerative process of the keratinocytes.