[A Case of Male Breast Cancer Suspected of Breast Metastasis from Pancreatic Cancer].

History of male breast cancer and pancreatic cancer are important for diagnosis of hereditary breast and ovarian cancer syndrome(HBOC), while advanced pancreatic cancer is reported to have metastasis to mammary gland tissue. A 67-year-old man visited a local hospital because fever and right hypochondrial pain. Computed tomography scan revealed pancreatic cancer with multiple liver metastasis and peritoneal metastasis. He was referred to our hospital for further evaluation and treatment. No particular family history of malignancy was formed. A palpable lump was found in his left breast. Ultrasonography revealed 2.8 cm sized mass that had heterogenous internal echo and rough border. The background mammary gland showed gynecomastia. Since it was difficult primary breast cancer with metastatic tumor originated from pancreas cancer a core needle biopsy was performed. The finding of pathological examination showed invasive carcinoma with hormonal receptor negative and HER2 negative feature. CK7 and CK19 were both positive. Although it was difficult to male differentiation whether the tumor was primary a metastatic, we diagnosed as synchronous duplicated cancer of pancreas and breast due to existence of gynecomastia. Since hepatic failure due to tumor growth advanced prior to treatment start, the treatment policy became best supportive care.