Abstract
Male breast cancer is a rare disease and represents about 1% of all breast cancers, and the incidence of intracystic breast cancer is reported to be less than 2-3% of all breast cancers. We report a case of intracystic carcinoma with microinvasion of the male breast. Only two such cases, including ours, have been reported in Japan.
An 83-year-old man presented with a right breast mass. An elastic soft well-demarcated tumor was present in the EACB area of the right breast. No axillary lymph node swelling was felt. Ultrasonography showed a 45×39×29 mm cystic tumor with blood flow just under the right nipple. Fine needle aspiration cytology suggested class III, so he underwent tumorectomy because a possibility of malignancy could not be ruled out.
Histological findings showed papillotubular carcinoma with microinvasion and positive margin so that mastectomy and sentinel lymph node biopsy were performed. Immunohistochemically, cancer cells were positive for both estrogen and progesterone receptors. He received endocrine therapy with oral tamoxifen for 5 years.
The patient has had no signs of recurrence as of 7 years after the operation.
