Does Exhaustive Search for Microcalcifications Improve Diagnostic Yield in Stereotactic Core Needle Breast Biopsies?

Abstract

Stereotactic core needle biopsy (SCNB) of the breast is a cost-effective alternative to needle localization biopsy for the diagnosis of mammographic calcifications. We questioned whether an exhaustive search for calcium in the small samples obtained in SCNB yields more diagnostic information than that obtained with examination of a standard number of sections. We retrospectively reviewed 168 specimens from 123 patients with mammographic calcifications, including cases in which radiographic suspicion ranged from low to high. Microcalcifications were identified on three initial levels in 112 specimens. Additional sections were examined in 50 specimens. The final diagnosis differed from the diagnosis based on three levels in 11/50 cases (22%). In 6/50 (12%), complete sectioning yielded a specific diagnosis. The increase in technical cost associated with the additional levels was 414% per case. We conclude that exhaustive searching for microcalcifications in SCNB yields a small increase in specific diagnostic information and a high technical cost. In individual cases, the additional information may be critical for appropriate patient management.

Histological correlation of mammographically detected breast calcifications – A need for rational protocols

“…43 The presence of birefringent, transparent calcium oxalate crystals should be always excluded before considering apparent calcium loss during histological breast specimen processing. 14,36,44 In Truong's series of 91 cases, calcium oxalate was clinically significant, i.e., actually represented the mammographic calcification, for which the biopsy was performed in 12% of all cases. 45 Calcium oxalate was also found in 31% of cases, even if it did not definitely represent the mammographic calcification for which the biopsy was performed in this study.…”

“…In most of the series studied, false-negative rates for core biopsies sampled for suspicious calcification are low. 14,16,18,37 In Dahlstorm and Jain's series of 125 cases, 18 there were two falseenegative results with a malignant outcome 37 In the series of Lee et al, one of the 106 cases sampled for radiologically suspicious cancer had a malignant outcome two years after the initial biopsy. 38 Bagnall et al found that the presence of five or more flecks of calcium, or three or more cores with calcification, on specimen radiography was associated with 100% sensitivity for diagnosis of malignancy.…”

“…17 Both Grimes et al as well as Kumaraswamy and Carder studies, have highlighted that a balance between cost effectiveness and the risks associated with increased work burden on both the reporting Pathologist and the laboratory staff preparing the sections must be considered before recommending the optimum number of sections required for histological demonstration of calcium in stereocores. 14,33 It must be also remembered that if atypical ductal hyperplasia (ADH) or carcinoma is identified on the first three levels, no further sectioning is necessary even if no calcifications have been identified because either diagnosis leads to a needle localisation biopsy or other appropriate surgical excision. 18 A caveat to this situation is when additional levels need to be examined in order to better characterise the malignancy.…”

“…3e13 The use of radiography (specimen X-ray) to assess the presence of calcification in core biopsy samples before processing has been recommended to confirm whether the suspicious mammographic calcification has been included in the core biopsy. 14,15 When calcification is present in the core biopsy radiograph but not in the histological sections, the histopathologist must consider the possibility of the calcium either being lost during processing or the tissue in the paraffin block been incompletely sectioned. Further sections from the paraffin block would need to be examined microscopically until the area including the calcification appears in the sections.…”

“…Grimes et al reviewed 168 core specimens and concluded that interpretation of radiographs of paraffin-embedded tissue was much more difficult for stereocores, in contrast to needle localisation biopsies, with 15% discrepancy in interpretation of radiographs of paraffin blocks. 14 Accurate characterisation of mammographic calcification requires radio-pathological correlation. In cases where the core biopsy shows malignant disease, the presence or absence of calcification in the histological sections has little relevance, although it has significance if benign disease is calcified adjacent to uncalcified malignant disease because this could give a false impression of the extent of the malignant disease.…”