BackgroundErythema gyratum repens is a rare, clinically specific, and distinctive paraneoplastic syndrome. It is associated with internal malignancy in 82% of patients.ObjectiveA 58-year-old man with erythema gyratum repens is described. On diagnosis of his eruption, a malignancy work-up revealed a 9-mm pulmonary adenocarcinoma. Removal of the carcinoma resulted in clearing of the erythema.ResultsErythema gyratum repens is most commonly associated with bronchial, esophageal, and breast cancer. It has also rarely been reported in patients without evidence of malignancy. The histopathologic findings are nonspecific. Direct immunofluorescence has sometimes revealed C3, C4, or immunoglobulin G at the basement membrane zone.ConclusionThe etiology of erythema gyratum repens is unknown, although an immune response is postulated. Treatment involves treating the underlying malignancy.