Gynecomastia is the most common diagnosis for male patients experiencing breast enlargement. It is also benign, though it can result in pain. According to a study published by the American Journal Roentgenology, when a patient is diagnosed with gynecomastia, further imaging tests such as mammography and ultrasound are not necessary if the patient has undergone chest CT within eight months.

Emily B. Sonnenblick, MD, of the Icahn School of Medicine at Mount Sinai in New York, New York, and colleagues studied data from 62 men who were diagnosed with gynecomastia after a mammogram and had also undergone CT within the last eight months. This was a retrospective study, and each diagnosis was made between January 2007 and June 2015.

Overall, the data revealed “a high level of concordance in morphologic features and distribution of gynecomastia” between the mammogram and the CT. In just one of the 62 cases, gynecomastia was evident in the mammogram and not the recent CT; this was due to cachexia.  

“Mammography performed within eight months of CT is unlikely to reveal cancer unless there is a suspicious clinical finding or a breast mass eccentric to the nipple,” the authors wrote. “Men with clinical symptoms of gynecomastia do not need additional imaging with mammography to confirm the diagnosis if they have undergone recent cross-sectional imaging.”

Sonnenblick et al. noted that the provider’s may still turn to mammography if suspicious symptoms are present. Two of the 62 men had ductal carcinoma that was missed by the CT scan and picked up the mammogram.

“In both cases of carcinoma, gynecomastia obscured the breast cancer on CT scans,” the authors wrote. “Thus, CT is not a substitute for mammography in men with suspicious symptoms. In a small number of symptomatic cases, mammography played a role in the diagnostic evaluation.”

Sonnenblick and colleagues noted that the study’s retrospective design meant it was not possible to “prospectively determine” if mammography could have truly been avoided for the 62 patients.  

“Radiologists must rely on an experienced examining clinician because longstanding gynecomastia may be associated with fibrosis and present as a firm mass, which can be difficult to differentiate from cancer,” the authors wrote. “In those circumstances, biopsy may be indicated in the context of a clinically indeterminate mass regardless of the imaging findings.”