April 3, 2000 (Chantilly, Va.) -- Medical experts say there are several reasons why a mammogram may fail to detect a cancerous tumor:
The technology. Mammograms involve squeezing a woman's breast between two plates of glass -- a technique that is awkward at best. Old or badly maintained equipment and poorly trained technicians can increase the odds of an inaccurate film.
The quality of a woman's breast. Mammograms aren't good at detecting cancers in breast tissue that is dense or fibrous, as is common among female athletes and premenopausal women.
The pace of medicine. With radiologists under pressure to read more films more quickly, the risk of making mistakes has grown.
Studies on mammogram accuracy show that screenings miss anywhere from 5% to 17% of abnormalities. Yet many patients continue to believe that a "clear" mammogram is the same as a clean bill of health.
Incidence and Mortality
Estimated new cases and deaths from breast cancer (men only) in the United States in 2014:
New cases: 2,360.
Male breast cancer is rare. Less than 1% of all breastcarcinomas occur in men.[3,4] The mean age at diagnosis is between 60 and 70 years, though men of all ages can be affected with the disease.
Predisposing risk factors  appear to include radiation exposure, estrogen administration, and diseases associated...
"Even though there is no perfect test, and no perfect doctor, and no perfect reading, patients expect perfect results,'' says Phan Huynh, M.D., a breast imaging specialist at the University of Texas Health Science Center in Houston.
Michael D. Towle writes regularly for WebMD on health and legal issues.