When visible on mammography, imaging findings of papilloma include asymmetrically dilated ducts, a circumscribed benign- appearing subareolar mass, or grouped microcalcifications [1]. Up to 12% of patients with ductal carcinoma in situ (DCIS) present with nipple discharge [33]. DCIS is usually detected mammographically as fine, linear, discontinuous, and branching microcalcifications in linear, ductal, or segmental distribution and less often as a mass, asymmetry/focal asymmetry, or architectural distortion on mammography [11]. The mammographic features of invasive carcinomas are well known, including a mass of various margin characteristics with or without microcalcifications or an asymmetry, focal asymmetry, or architectural distortion [34]. For detection of malignancy (DCIS and invasive cancer), the reported sensitivity of mammography varies widely between 15% and 68%, with a specificity between 38% and 98% [3,9,23,28]. In one study, the positive predictive value (PPV) was 42%, and the negative predictive value (NPV) was 90% [23]. Malignant and high-risk lesions are identified by mammography with a reported sensitivity of 10% to 26%, specificity of 94% to 95%, PPV of 18%, and NPV of 88% [3,16]. The possible causes of the wide variation in reported sensitivity include differences in imaging technology (digital versus film-screen mammography) and varied breast density among different cohorts of patients. In a study of 106 patients >30 years of age with pathologic nipple discharge, Gray et al [28] showed the risk of carcinoma to be 3% with a negative mammogram and 0% when both mammogram and subareolar US were negative. Although low in sensitivity and PPV, mammography remains useful in the evaluation of pathologic nipple discharge because of its high specificity and high NPV.
Evaluation of Nipple Discharge. When visible on mammography, imaging findings of papilloma include asymmetrically dilated ducts, a circumscribed benign- appearing subareolar mass, or grouped microcalcifications [1]. Up to 12% of patients with ductal carcinoma in situ (DCIS) present with nipple discharge [33]. DCIS is usually detected mammographically as fine, linear, discontinuous, and branching microcalcifications in linear, ductal, or segmental distribution and less often as a mass, asymmetry/focal asymmetry, or architectural distortion on mammography [11]. The mammographic features of invasive carcinomas are well known, including a mass of various margin characteristics with or without microcalcifications or an asymmetry, focal asymmetry, or architectural distortion [34]. For detection of malignancy (DCIS and invasive cancer), the reported sensitivity of mammography varies widely between 15% and 68%, with a specificity between 38% and 98% [3,9,23,28]. In one study, the positive predictive value (PPV) was 42%, and the negative predictive value (NPV) was 90% [23]. Malignant and high-risk lesions are identified by mammography with a reported sensitivity of 10% to 26%, specificity of 94% to 95%, PPV of 18%, and NPV of 88% [3,16]. The possible causes of the wide variation in reported sensitivity include differences in imaging technology (digital versus film-screen mammography) and varied breast density among different cohorts of patients. In a study of 106 patients >30 years of age with pathologic nipple discharge, Gray et al [28] showed the risk of carcinoma to be 3% with a negative mammogram and 0% when both mammogram and subareolar US were negative. Although low in sensitivity and PPV, mammography remains useful in the evaluation of pathologic nipple discharge because of its high specificity and high NPV.