Is gynecomastia associated with cancer?

Gynecomastia is a benign proliferation of breast tissue in males. It is not associated with cancer. However, breast cancer can occur in men and in fact 1% of all breast cancers diagnosed in the United States occur in men. Rapidly growing gynecomastia or unilateral gynecomastia in the setting of a family history of breast cancer may require further evaluation with Diagnostic Mammography before proceeding with treatment.