BackgroundGynecomastia has a typical appearance on mammography, and occurs frequently in men. However, imaging is often performed on men with breast lumps to exclude breast cancer, which only comprises 1% of male breast masses.PurposeTo assess whether ultrasound and fine needle aspiration cytology (FNAC) are necessary investigations when mammograms show classical gynecomastia.Material and MethodsWe have retrospectively collected data on male patients referred for mammography during the period 2011?2013 (a total of 539 patients). All radiological images were re-read, and descriptions of ultrasound images were reviewed. Clinical information supplied with the original referrals was assessed, along with pathology and cytology reports.ResultsAmong the 539 male patients who underwent mammography, 483 were also examined with ultrasound, and 335 were further evaluated with FNAC. Mammograms showed gynecomastia in 350 patients, and among these subjects ultrasound was performed in 340 (97%), FNAC in 261 (75%), and core biopsies in four (1%) patients. The diagnosis gynecomastia was unchanged in all patients who underwent FNAC or biopsy. Malignant tumors were found in eight patients, six of which were invasive ductal carcinomas.ConclusionIn patients with a classical appearance of gynecomastia on mammography, supplemental ultrasound, FNAC, or biopsy is superfluous and contributes to unnecessary costs.