Although rare, yes, men can be diagnosed with breast cancer. Breast cancer develops in breast tissue, which both men and women have. According to the American Cancer Society, breast cancer is about 100 times less common among men than women and the lifetime risk of male diagnosis is about 1 in 833.
Breast cancer in men is not the same as breast cancer in women, cancer cells grow differently, since the breast makeup varies between the two. Cancer in men is less common because male breast duct cells are less developed than a female's. This is because men have lower levels of hormones that affect the growth of those cells.
It is important for men to know that breast cancer is a possibility and to know what to look for should they notice changes in their breasts. Common symptoms include a lump or swelling, skin dimpling, nipple retraction (turning inward), redness and discharge from the nipple.
Sometimes, breast cancer can spread to lymph nodes under the arm or around the collar bone in men and can cause a lump or swelling there, even before the original tumor in the breast is large enough to be noticed.
It is also important to know that many times in men, lumps in the breast can be gynecomastia, a harmless enlargement of breast tissue. Talk to your doctor if you notice lumps or changes in the breast that could be a concern.