Nonpalpable breast cancer: mammographic appearance as predictor of histologic type.

PURPOSE: To investigate the association between mammographic appearance and histologic diagnosis of nonpalpable breast cancers. MATERIALS AND METHODS: Mammographic characteristics of 317 consecutive clinically nonpalpable breast cancers in patients treated with breast-conserving surgery were reviewed. Malignant lesions were categorized as spiculated masses, other lesions, calcifications, and combined findings. Calcifications were characterized as amorphous, pleomorphic, or fine linear and branching. Logistic regression was used for the evaluation. Odds ratios (ORs) represent the magnitude of the association between a histologic diagnosis and a mammographic finding. RESULTS: Spiculated mass without calcifications (n = 150) and calcifications alone (n = 79) accounted for three of four cancers. A spiculated mass without calcifications was strongly associated with invasive cancers (OR = 12). Calcifications alone were strongly associated with ductal carcinoma in situ (DCIS) (OR = 19). In a decreasing order, the following invasive cancers were each associated with spiculated lesions without calcifications: ductal carcinoma grade 1 (OR = 28), ductal carcinoma grade 2 (OR = 17), lobular carcinoma (OR = 11), and ductal carcinoma grade 3 (OR = 4.6). Fine linear and branching calcifications alone were associated with not only DCIS nuclear grades 3 (OR = 17) and 2 (OR = 9.7) but also with invasive ductal carcinoma grade 3 (OR = 13). CONCLUSION: Mammographic appearance can be a predictor of histologic diagnosis in three of four nonpalpable breast cancers.