Corynebacterium species are an uncommon cause of breast abscess, and Corynebacterium amycolatum is rarely described in the literature. In the present case, we report recurrent breast abscess caused by C. amycolatum in a 39-year-old patient with normal immune function. Pathological diagnosis was granulomatous mastitis. The patient was treated with incision and drainage and ampicillin-sulbactam treatment. To our knowledge, this is the second report of breast abscess caused by C. amycolatum.

Corynebacterium species are an uncommon cause of breast abscess, and Corynebacterium amycolatum is rarely described in the literature. In the present case, we report recurrent breast abscess caused by C. amycolatum in a 39-year-old patient with normal immune function. Pathological diagnosis was granulomatous mastitis. The patient was treated with incision and drainage and ampicillin-sulbactam treatment. To our knowledge, this is the second report of breast abscess caused by C. amycolatum.