Prediction of the underlying histology from the mammogram: mammographic-large section histologic correlation of >1000 open surgical biopsies

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The radiologist greatly enhances her or his skills by regular review of the preoperative mammograms once the histologic diagnosis became available.

Most breast cancers are invasive at diagnosis, even when they are detected at mammographic screening. The invasive cancers must be found in their preclinical stage to prevent the development of advanced breast cancer, a prerequisite for decreasing mortality. The majority of the mortality benefit in the Two-County Swedish Trial was achieved by shifting Stage II and more advanced cancers to Stage I, ie detecting invasive tumors at an early stage, rather than by shifting invasive tumors to in situ. Although 39% of all malignancies did contain calcifications in a mammographic-large section histologic correlation of > 1000 consecutive open surgical biopsies, a minority of the malignant breast tumors had calcifications as the only mammographic sign of malignancy. Detecting subtle spiculated and circular or oval lesions should be a priority. Most of the breast cancers, 80%, depicted spiculated or circular/oval breast masses, of which three-quarters were without associated calcifications. Two thirds of the breast cancers were spiculated; finding them when still small is the major challenge for the radiologist. Once a spiculated lesion has been found, the probability that it is a cancer is 92%.

Only one-third of the malignant tumors were circular/oval on the mammogram. The malignancy ratio of the circular/oval lesions undergoing open biopsy is lower than for the spiculated lesions.

The three main malignant types of calcifications were predictive of cancers in a varying way. Correlating the mammographic findings with underlying histology will help the radiologist find the tumors which would become fatal without early detection.