Breast cancer in men.

Less than 1% of all breast cancers occur in men, and although the disease is rare, the incidence appears to be increasing. Because men usually do not suspect breast cancer when they feel a lump in the breast, diagnosis frequently is delayed. Although screening for breast cancer is not recommended for men, radiographic imaging plays an important role in distinguishing benign conditions from malignant disease, and mammography usually is recommended as the first radiographic assessment. Ultrasonography is useful in differentiating between noncancerous cysts and solid malignant tumors, especially if coexisting gynecomastia masks a cancerous lesion on mammography. Sonography also is useful to guide breast biopsy.