Biopsies for Mammographic Abnormalities
Nonpalpable lesions detected mammographically are often biopsied by the surgeon and the specimen then sent to radiology, where a specimen radiograph is obtained to confirm that the surgeon has indeed biopsied or excised the lesion detected on the clinical mammogram. In these cases the radiologist frequently marks the lesion with a needle or dye, and both the biopsy and the specimen mammogram are then sent to the surgical pathology laboratory.
Once received in pathology, the specimen should be measured, inked, and serially sectioned (Figure 25-1). Take care to slice the breast thinly (2 mm). Take advantage of the specimen radiograph; the gross findings can be correlated with the lesion seen radiographically. If a lesion is seen, note the largest dimension of the lesion and carefully note the relationship of the lesion to the inked margins as well as the circumscription and nature of the border of the lesion.
Sequentially submit the entire specimen, up to 20 blocks of tissue, for histologic examination. Sequential sectioning allows one to better reconstruct the distribution of the lesion from the slides. When taking these sections, be sure that the sections demonstrate the relation of the lesion to the closest inked margin. Be sure also to designate which block contains the area marked by the radiologist’s needle as containing calcification.
For large biopsy specimens that cannot be completely submitted in 20 or fewer sections, the extent of tissue sampling is not clear. Owings et al. suggested a method for selective tissue sampling in these large specimens. According to their method, initial sampling should include the submission of all tissue corresponding to radiographic calcifications and all surrounding fibrous tissue.
If carcinoma or atypical duct hyperplasia is identified in these initial sections, the remaining tissue should be submitted in its entirety to determine the extent of the lesion and the status of the margins and to exclude inva-sion in cases of ductal carcinoma in situ.