INTRODUCTION: Accessory breast tissue is a rare finding in the general population with an incidence of 1-2%. Carcinomas of accessory breast tissue account for ∼0.3% of breast cancers, 5% of which are arising within a supernumerary breast. They are usually diagnosed at a later stage compared with breast cancer, due to their rarity and low clinical suspicion. CASE PRESENTATION: We present the case of a 58 years old male who was admitted to our hospital for an umbilical hernia, surgical repair. During surgery a small skin biopsy was excised and sent for pathological examination as routine procedure. The histological report revealed the presence of a poorly differentiated carcinoma. Immunochemical analysis confirmed adenocarcinoma of breast origin. CONCLUSION: Carcinomas of accessory breast tissue are rare and therefore they are usually of advanced stage in time of diagnosis. Few cases have been reported in literature of accessory breast tissue carcinomas in men. To the best of our knowledge, this is the only case in the literature, of ectopic breast tissue cancer in the umbilicus.