Treatment is necessary if gynecomastia is caused by a disease or a tumor. If it is due to a disease, the disease itself will need to be treated. Breast cancer is very rare in males. Your doctor will probably be able to tell whether the lump is cancer. Lumps caused by cancer are usually not underneath the nipple, but breast tissue from gynecomastia grows in this area.
Breast cancer feels different than the breast tissue of gynecomastia.
With cancer, there sometimes is dimpling of the skin or a bloody discharge from the nipple. If there is any question that you have cancer, you will need to have a mammogram and a biopsy. This handout provides a general overview on this topic and may not apply to everyone. To find out if this handout applies to you and to get more information on this subject, talk to your family doctor. Visit familydoctor.org for information on this and many other health-related topics.