Common and unusual diseases of the nipple-areolar complex

The nipple-areolar complex is often best evaluated as a separate region of the breast. Because of the intricacy of the anatomic structures and their superficial position, the diagnostic techniques required for optimal evaluation of the nipple-areolar complex differ from those routinely used to evaluate the whole breast. Although clinical examination and screening mammography are still of central importance, the adjunct use of multiple imaging modalities (ultrasonography, contrast material-enhanced magnetic resonance imaging, or both) as well as nonstandard mammographic views is often necessary to differentiate benign abnormalities from malignant ones. For accurate diagnosis, familiarity with a wide range of appearances of the normal anatomy, including congenital anomalies (eg, supernumerary nipples), is necessary, as is a thorough knowledge of the features of the benign and malignant processes that commonly occur in the nipple-areolar complex. Benign abnormalities may include mammary duct ectasia, nipple calcifications, cutaneous horn of the nipple, abscess of the Montgomery gland, and nipple adenoma. Malignant abnormalities may include Paget disease and primary lymphoma as well as carcinoma of the breast. Some conditions, such as nipple retraction and inversion, may have either a benign or a malignant cause. In such cases, a thorough radiologic assessment is especially important.