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There is controversy as to the value of the radiological or pathological estimation of surgical clearance of microcalcifying breast lesions. An important part of this issue has been addressed by coordinated three-dimensional radiographic and histological examination of a prospective consecutive series of 40 benign and malignant mammographically detected lesions in surgical breast biopsy specimens containing microcalcifications, including 20 cases of ductal carcinoma in situ. They were radiographed from four viewpoints by means of rotation in a radiolucent tetrahedral container. The planes of histological examination were then chosen to correspond to the radiographic view showing the minimum separation of the edge of the specimen and the outermost microcalcification. There was a close correlation (Spearman ranked) between the least tetrahedral radiographic distance and the corresponding histological distance separating the surgical margin of excision. There were, however, incompatible Wilcoxon signed ranking orders when comparing the least tetrahedral distance or the histological distance with all four single radiographic views, including the conventional specimen radiographic view. Two-dimensional specimen mammography and standardized histological examination are suboptimal and may thus have contributed to confusion as to the value of determining adequate surgical excision of ductal carcinoma in situ of the breast. Although labour-intensive, use of four-view radiography and choice of the appropriate plane of histological examination give a better correlation of the radiographic estimates of surgical clearance with histology than single-view specimen radiography and arbitrary histological sectioning.

Tissue slices (500 to 1000 microns thick) of archival formalin-fixed, paraffin-embedded breast tissue were immunostained by a cytokeratin antibody (MNF116) using a streptavidin-biotin complex procedure. The technique requires prolonged exposure of tissue slices to the reagents. Use of the detergent Triton X-100 facilitated penetration of high molecular weight reagents through the tissue slices. Fifty of 58 slices 500 microns thick (86%) showed good to excellent immunostaining, and 13 of 20 slices 1000 microns thick (65%) showed similar staining. Omission of the primary antibody eliminated any immunostaining. Comparison with corresponding Haematoxylin staining of the thick slices (the conventional procedure for such breast tissue slices) showed that thick-slice cytokeratin immunostaining markedly improved visualization of the epithelial structure in normal lobules and invasive carcinomas. Although the immunohistochemical technique takes 33 days for completion, the quality of the epithelial images outweighs this disadvantage.