Though breast cancer and tumors are principally thought of as affecting women, these conditions can also affect men, although men account for less than 1 percent of breast cancer cases in the United States. Tumors of the breast may be benign, meaning they are not cancerous, or malignant, meaning they are cancerous. There are several different types of tumors that may grow in the breasts of men, some of which are benign, and some malignant.
Papillomas
One type of benign breast tumor that can affect men is a papilloma, according to the American Cancer Society. The University of California, Los Angeles, or UCLA, Health System describes a papilloma as an overgrowth of tissue that grows into the inside of the milk duct. Though milk ducts, which channel milk to the nipple, and the milk-producing lobules, are much more plentiful in females, men have these types of breast tissue as well. When a papilloma grows into a milk duct, the resulting inflammation can cause a discharge from the nipple.
Fibroadenoma
A fibroadenoma is another type of benign breast condition that affects men, as reported by the American Cancer Society. The UCLA Health System describes the lump formed by a fibroadenoma as a firm mass with a well-defined border. Fibroadenomas often look differently on a mammogram than breast cancer, but confirmation that the lump is not cancerous can only be provided by a biopsy, which is a surgical sampling of the tissue.
Carcinoma
The American Cancer Society describes a carcinoma as a type of male breast tumor that is cancerous. A carcinoma is any type of cancer that begins in the epithelial cells, which are cells that line the outer edges of breast tissue. One very common type of carcinoma is ductal carcinoma, meaning the cancer begins in the epithelial cells that line the milk ducts. Ductal carcinoma may be infiltrating, meaning the cancer has spread beyond the ducts. Ductual carcinoma may also be "in situ," which means that the cancer has not spread beyond the duct.
Paget's Disease of the Nipple
This type of malignant tumor grows from the ducts of the breast out towards the surface of the nipple. The American Cancer Society notes that Paget's disease of the nipple causes the skin of the nipple to be scaly, red, itchy, and or burning. The tumor may be able to be detected by feeling the breast.
