[Microcalcifications in non-palpable breast carcinoma. Analysis of 427 cases].

Of 836 nonpalpable breast lesions histologically assessed between 1985 and 1991 at the Milan Cancer Institute, 427 were malignant (51%). Microcalcifications were present in 283 tumors (66%), alone in 200 cases or associated with a mass (72 cases) or within a focal distortion (11 cases). Several mammographic, clinical and histological features were analyzed, comparing the 283 lesions with microcalcifications with the 144 tumors represented only by nodular opacities or distortions. This was done to assess the existence of morphologic and prognostic characters differentiating the two subsets and to investigate the reliability of mammography in estimating lesion size. On the average, in our series of cases, the patients with microcalcifications were younger, had a higher rate of dense breasts and a large number of partially or totally intraductal carcinomas. In situ carcinomas were frequent and minimal lesions (< 5 mm) accounted for 43% of the whole at pathologic examination. However, the lesions with microcalcifications were associated with more positive nodes (32% vs 18%). Therefore, microcalcifications, although generally representing an early sign of cancer, appear to suggest a less favorable prognosis.