First Report of Merkel Cell Carcinoma in Two Brothers

Merkel cell carcinoma (MCC) is a very rare aggressive malignant tumor.Risk factors include older age, exposure to ultraviolet radiation, immunodeficiency status, and infection with Merkel cell polyomavirus (MCPyV).MCC not been considered to run in families, and a review of the medical literature failed to reveal any cases of MCC in first-degree relatives.The aim of this report was to describe for the first time the development of MCC in two brothers.The extremely low likelihood of siblings acquiring the disease, compounded by the similar clinical presentation of the tumor on the skin of the right thigh in both brothers, suggests a possible unknown predisposing factor.Genetic predisposition analysis should be performed in family members of patients with MCC.