The role of the surgical pathologist in the examination of the non-palpable breast lesion.

The specimen excised for the mammographically detected lesion is somewhat unique and requires special consideration by the surgical pathologist. The biopsy, in most instances, contains no grossly visible lesion and is relatively large so that blocking in its entirety is not practical. The pathologist needs to establish that the radiological abnormality is contained in the biopsy and to this end specimen radiography is required. Established prognostic parameters for breast carcinoma, such as tumor size, histological type, grade and hormone receptor status are equally applicable in the non-palpable breast lesion but consideration should also be given to the identification of epithelial proliferations which have increased risk for subsequent carcinoma. In addition, the recognition of ductal carcinoma in situ in the biopsy indicates potential for widespread disease, and lobular carcinoma in situ, a less commonly detected lesion in mammography, is associated with multifocality and disease in the contra-lateral breast. Both lesions are also associated with increased risk of recurrence in the remaining breast tissue. Failure to observe the corresponding quantity of calcium seen in radiographs relates to the fact that calcium may occur, not only as calcium phosphate, but also as calcium oxalate, the latter not being stained by hematoxylin and eosin but readily detected by its birefringent nature in polarized light. Detailed correlation of serial thin slices of the specimen with radiographic features is largely an educational exercise but is the most time-consuming step in the examination of the non-palpable breast lesion.(ABSTRACT TRUNCATED AT 250 WORDS)