There are several different types of breast cancer, but nearly all are considered adenocarcinomas because most develop in either the ducts or lobules, both of which are glandular tissue. Some cancers are followed by the words in situ, meaning the cancer is contained to a single area. If the cancer breaks through to the surrounding lobules or ducts, it is called infiltrating or invasive carcinoma. From there, the cancer can spread to blood vessels, lymph nodes and other parts of the breast. If not detected early, it can spread to other parts of the body resulting in a poorer prognosis.The staging of cancer is identical for men and women with breast cancer.

The most common types of breast cancer include:

• Ductal carcinomas. Affecting the milk passages (ducts) of the breast. These are the most common breast cancers in both men and women. The two main types are:
  
  
• Infiltrating (or invasive) ductal carcinoma (IDC). This is by far the most common in men, accounting for 80 to 90 percent of all male breast cancers, according to the American Cancer Society (ACS). As the mass grows, it can lead to a dimpling of the breast or the nipple retracting inward.
  
  
• Ductal carcinoma in situ (DCIS). Also known as intraductal carcinoma or noninvasive ductal carcinoma, DCIS is an uncommon type of breast adenocarcinoma in men. It accounts for about 10 percent of male breast cancers, according the ACS.
  
  
• Lobular carcinomas. Affecting the milk-producing glands (lobules). These are rarely seen in men since men’s breast tissue has ducts, but few lobules.
  
  
• Inflammatory breast cancer. This form of the disease that has been diagnosed in men is highly malignant. Inflammatory breast cancer spreads rapidly, producing symptoms of swelling, redness and skin that is warm to the touch in the area of tumor involvement.
  
  
• Paget's disease. This disease is slow-growing cancer of the areola and nipple. Paget’s disease eventually grows onto the nipple itself. It is sometimes mistaken for eczema as it can create itchiness or a crusty appearance around the nipple. According to the ACS, it accounts for about 1 percent of female breast cancers, but a higher percentage of male breast cancers. Because of the smaller size of the male breast, tumors are more likely to start relatively close to the nipple and/or spread to the nipple.