[Hamartoma of aberrant breast tissue in the inguinal region].

Ectopic mammary tissue reportedly has an incidence of 1 to 6%, and is usually found in the axilla. Neoplasias in ectopic breast tissue are rarely observed. This is the first report of an hamartoma of ectopic breast tissue in the inguinal region. A 50-year old woman presented with a large tumor in the groin. The unusual site and form of the tumour preoperatively suggested a chronic incarcerated hernia. When laparoscopy excluded a hernia, the tumour was resected in accordance with oncological criteria and the histopathological work up revealed the surprising findings. This case shows that ectopic mammary tissue, in particular when it is the site of a tumor, may be a rare differential diagnosis of an inguinal tumor.