This is not an entirely hypothetical question.
Breast cancer is primarily a women's disease.
According to one estimate, about one woman out of every nine will develop breast cancer at some point in her lifetime. But men are not immune to breast cancer. Up to 400 men die every year from breast cancer. Radiologists at UT Southwestern Medical Center at Dallas say doctors can tell the difference between gynecomastia and lumps caused by cancer with a physical exam and through mammography. Mammography isn't limited to women, and it can be an essential part of a male breast cancer diagnosis.