[Occult primary MALT lymphoma of the breast diagnosed and treated by reduction mammaplasty. An exceptional case report and review of the literature].

Primary Mucosa-associated Lymphoid Tissue (MALT) lymphoma of the breast is a very rare disease. We report here a case of occult primary MALT lymphoma of the breast diagnosed from a mammaplasty specimen. Primary tumor resection during the mammaplasty surgery was the only treatment of this lymphoma, and there was no recurrence at five years. The clinical and radiologic presentation of primary MALT lymphoma of the breast is similar to epithelial breast carcinoma, and the main diagnostic criteria are microscopic examination and immunohistochemistry. The prognosis of breast primary MALT lymphomas is good after local treatment by surgery and/or radiotherapy, and surgery shouldn't be too aggressive. In this case, no other treatment was indicated after the first surgical procedure. To our knowledge, this is the first case report in the literature of occult primary MALT lymphoma of the breast diagnosed from a mammaplasty specimen. This allows us to highlight the need for systematic microscopic examination of mammaplasty specimens conducted by an experienced pathologist, especially as preoperative examinations are not able to detect all occult breast carcinomas.