Overuse of imaging the male breast-findings in 557 patients.

Gynecomastia is the most common abnormality of the male breast. However, breast cancer may occur, albeit with a significantly lower incidence than in females. Imaging is often used as part of the diagnosis. The aim of this study was to assess the utilization and outcome of imaging with mammography or ultrasound of the male breast in a university hospital's department of radiology. A retrospective study assessing the imaging of the male breast in 557 patients over a 10-year period. Referral was done mainly by general surgeons and general practitioners. The most common indication was enlargement of the breast, described as gynecomastia or swelling in 74% of patients, followed by pain in 24% and "lumps" in 10%. The modalities used were mammography in 65%, ultrasound in 51% and both in 26%. Most examinations, 519, were BI-RADS 1 or 2, and 38 were BI-RADS 3 or higher. Altogether 160 patients had additional fine-needle aspiration or biopsy. Malignancies were diagnosed in five patients (0.89%). Imaging had a sensitivity of 80% and a specificity of 99%. The positive predictive value was 44% and the negative predictive value 99.8%. Malignancies are rare in the male breast. The probability of finding cancer when performing imaging of clinically benign findings in the male breast is negligible. Imaging is not warranted unless there are suspicious abnormalities. Routine imaging of gynecomastia should be discouraged.