Occult breast cancers manifesting as axillary lymph node metastasis in men: a two-case report

Occult breast cancer is a type of breast cancer without any symptoms on the breasts or any abnormalities upon radiologic examination such as mammography. In males, there are few cases of breast cancer, the rate of diagnosis of occult breast cancer is very low, and little is known about this disease. We experienced two cases of occult breast cancers manifesting as axillary lymph node metastasis in men. They had a palpable lesion on axillary area several years ago and had not seen a doctor about it. As such there was no abnormality on evaluations for cancer except for axillary lymph node showing signs of carcinoma (primary or metastatic) on biopsy and estrogen receptor-positive and progesterone receptor-positive on immunohistochemistry. The patients were diagnosed with occult breast cancer, and treatments were performed. Herein, we report the rare cases of occult breast cancers in men.