Intracystic papillary carcinoma of the breast in male: case report and review of the Japanese literature.

We report a case of intracystic papillary carcinoma of the breast in a 62-year-old Japanese man, who came to our hospital complaining of a right subareolar mass. Imaging diagnosis was a cyst with an intracystic component. Since repeated aspiration biopsy cytology was interpreted as a borderline lesion, no additional treatment had been given. Because he wanted the removal of the mass 14 months after his first visit, an excisional biopsy was performed under local anesthesia. Pathological examination revealed the intracystic component to be non-invasive papillary carcinoma. Although the incidence of male breast cancer is approximately 1% of all breast cancer, intracystic papillary carcinoma in the male is very rare. From a review of the literature on this disease in Japanese men, an intracystic component can often be demonstrated by ultrasound. However, it is difficult to confirm malignant cells by aspiration biopsy cytology of cyst fluid. Since some cases have a local relapse, excisional biopsy and long-term follow-up are indicated.