What might one-sided gynecomastia signify?
What workup is required in men who notice a small amount of unilateral gynecomastia? Should they be sent for any imaging studies or blood work if on physical exam it feels like normal breast tissue and they’re otherwise well? ALLISON PROKOPIAK, MD, Ottawa, ON
Gynecomastia has been reported to have an incidence of between 5% and 9% from autopsy studies but in other groups 40% of normal men have palpable breast tissue. There is asymmetry in most people and therefore the diagnosis of unilateral, as opposed to markedly asymmetrical, gynecomastia is often difficult unless it’s very pronounced. Very pronounced unilateral gynecomastia, although possible, must be distinguished from benign chest wall tumours (lipomas, neurofibromas, etc.). Malignant disease is usually eccentric in location, hard and can have skin changes. Physiological gynecomastia is common in newborns, in adolescents around puberty and in the aged. Pathological gynecomastia would occur from decreased testosterone, increased estrogen, drugs or malignancy, with the last the least common. Workup for someone suspected of gynecomastia involves a very careful history of drugs, testicular exam, an evaluation of liver function and potentially, hormonal levels of estrogen, luteinizing hormone (LH), testosterone, and androstenedione. Satisfactory diagnosis, however, can only be made in about 50% of these cases. If the drug history is negative in a 45+ year-old man and the breast tissue is > 4 cm or tender, you should be more suspicious of malignancy, though the breast rarely feels normal.
Men who present with unilateral gynecomastia should be initially investigated with a history and clinical exam. History of medications, liver, renal or thyroid diseases and symptoms of hypogonadism must be obtained. Include an abdominal exam in the physical, to look for masses, and a testicular exam. Screening bloodwork should be done for any new gynecomastia. Include human chorionic gonadotropin (HCG) and estrogen luteinizing hormone, follicle stimulating hormone testosterone, thyroid stimulating hormone, liver enzymes, creatinine and prolactin. If HCG or estrogen is elevated, a testicular ultrasound should be ordered. If that reveals nothing, then do an abdominal CT scan, to look for adrenal masses. If prolactin is too high, an MRI of the pituitary ought to be considered.