Stereotactic vacuum-assisted breast biopsy: Comparison between 11- and 8-gauge needles

Value of stereotactic 11-gauge vacuum-assisted breast biopsy in non-palpable suspicious calcifications: an eight-year single institution experience with 587 patients

Background

Vacuum-assisted breast biopsy (VABB) has been routinely recommended for stereotactic intervention in cases of isolate mammographically-detected calcifications. Herein we aimed to evaluate and compare the diagnostic consistency and accuracy of calcified and noncalcified specimens obtained from same sites of sampling on mammography-visible calcifications. In addition, we presented the biopsy procedure and retrospectively evaluated the usefulness of VABB as well as the complications of this technique over an eight-year experience in our centre.

Methods

This single-institution observational cohort study included 587 patients referred for stereotactic 11-gauge VABB of 594 mammographically-detected calcifications between January 2010 and December 2018. The rate of histopathological underestimation, the false negative, the diagnostic consistency and accuracy between calcified and noncalcified specimens of VABB were comprehensively evaluated based on the surveillance data and final histopathological result of the surgical specimens.

Results

In total, 594 biopsy procedures were performed in 587 patients (mean age 46 years, range, 21-80 years). The average number of biopsy specimens was 14.7 (range, 9-21) per lesion. VABB pathological results revealed 471 (79.3%) benign, 39 (6.6%) high-risk, and 84 (14.1%) malignant cases. The diagnostic inconsistency between calcified and noncalcified specimens was 14.6% (105/123) for high-risk and malignant lesions. Furthermore, calcified specimens exhibited higher diagnostic accuracy of malignant lesion as compared with the noncalcified specimens (97.7% versus 82.6%, respectively). Underestimation rate for high-risk lesions and in situ carcinoma was 5.1% and 54.1%, respectively, along with a false negative rate of 6.25%. In addition, mild complications were reported with high patient tolerance.

Conclusions

Stereotactic 11G-VABB might be preferred for the investigation of non-palpable mammographically-detected calcifications in terms of accuracy and safety profile. The high prevalence of diagnostic discordance between the specimens with and without calcifications revealed a higher value of calcified specimens in diagnosing high-risk and malignant calcifications.

Positive predictive value for malignancy of uncertain malignant potential (B3) breast lesions diagnosed on vacuum-assisted biopsy (VAB): is surgical excision still recommended?

PURPOSE

Breast lesions classified as of "uncertain malignant potential" represent a heterogeneous group of abnormalities with an increased risk of associated malignancy. Clinical management of B3 lesions diagnosed on vacuum-assisted breast biopsy (VABB) is still challenging: surgical excision is no longer the only available treatment and VABB may be sufficient for therapeutic excision. The aim of the present study is to evaluate the positive predictive value (PPV) for malignancy in B3 lesions that underwent surgical excision, identifying possible upgrading predictive factors and characterizing the malignant lesions eventually diagnosed. These results are compared with a subset of patients with B3 lesions who underwent follow-up.

METHODS

A total of 1250 VABBs were performed between January 2006 and December 2017 at our center. In total, 150 B3 cases were diagnosed and 68 of them underwent surgical excision. VABB findings were correlated with excision histology. A PPV for malignancy for each B3 subtype was derived.

RESULTS

The overall PPV rate was 28%, with the highest upgrade rate for atypical ductal hyperplasia (41%), followed by classical lobular neoplasia (29%) and flat epithelial atypia (11%). Only two cases of carcinoma were detected in the follow-up cohort, both associated with atypical ductal hyperplasia at VABB.

CONCLUSION

Open surgery is recommended in case of atypical ductal hyperplasia while, for other B3 lesions, excision with VABB only may be an acceptable alternative if radio-pathological correlation is assessed, if all microcalcifications have been removed by VABB, and if the lesion lacks high-risk cytological features.

KEY POINTS

• Surgical treatment is strongly recommended in case of ADH, while the upgrade rate in case of pure FEA, especially following complete microcalcification removal by VABB, may be sufficiently low to advice surveillance as a management strategy. • The use of 11-G- or 8-G-needle VABB, resulting in possible complete diagnostic excision of the lesion, can be an acceptable alternative in case of RS, considering open surgery only for selected high-risk patients. • LN management is more controversial: surgical excision may be recommended following classical LN diagnosis on breast biopsy if an additional B3 lesion is concurrently detected while in the presence of isolated LN with adequate radiological-pathological correlation follow-up alone could be an acceptable option.

A ten-year, single-center experience: Concordance between breast core needle biopsy/vacuum-assisted biopsy and postoperative histopathology in B3 and B5a cases

Purpose

To determine the concordance rate between core needle biopsy/vacuum-assisted biopsy (CNB/VAB) and postoperative histopathology in B3 (lesions of uncertain malignant potential) and B5a (in situ) lesions found on mammograms or ultrasound.

Material and methods

2,029 consecutive biopsies performed over 10 years for patients who underwent mammograms or ultrasounds. For CNB 14G needle and for VAB 8G/10G needles were used. In all biopsies, we identified the age, BI-RADS®, histopathological biopsy results, B-category, nuclear grade for DCIS and postoperative histopathology results in B3 and B5a cases from the biopsy.

Results

The B-categories from CNB/VAB were as follows: B2 42.2 percent (n = 856), B3 4.5 percent (n = 91), B5a 5.7 percent (n = 115), and B5b 47.6 percent (n = 967). In the B3-category, 72/91 patients underwent surgical excision, with a concordance rate of 83.3 percent (n = 60/72) and a discordance rate of 16.7 percent (n = 12/72) to postoperative histopathology. From the discordant cases, 67.7 percent (n = 8/12) showed DCIS and 32.3 percent (n = 4/12) showed invasive breast cancer. The BIRADS of the discordant cases was 4b in 41.7 percent (n = 5/12) and 5 in 58.3 percent (n = 7/12). The PPVs for malignancy of B3 lesions were 0.21, with no statistical significance between subgroups. In the B5a-category, 101 of 115 patients underwent surgery in our hospital, with a concordance rate of 80.2 percent (n = 81/101) and a discordance rate of 19.8 percent (n = 20/101) to postoperative histopathology. From the discordant cases, 55 percent (n = 11/20) showed invasive breast carcinoma of no special type (NST).

Conclusion

Our concordance rate for B3 (83.3 percent) and B5a (80.2 percent) lesions in the biopsies to postoperative histopathology is matching to previously published literature. Surgical excision is our recommendation for lesions biopsied with a B3 category in the histopathology and a BIRADS category of (4b, 4c and 5). The PPVs for malignancy of B3 lesions showed no statistical significance between subgroups. Also, the nuclear grade of DCIS was not statistically significant in terms of upgrade into invasive breast cancer.

Stereotactic 9-gauge vacuum-assisted breast biopsy, how many specimens are needed?

PURPOSE

To determine the minimum number of stereotactic 9-gauge vacuum-assisted biopsy specimens required to establish a final histopathological biopsy diagnosis of mammographically suspicious breast lesions.

METHODS

This prospective single-center observational cohort study included 120 women referred for stereotactic vacuum-assisted biopsy of 129 mammographically suspicious lesions between December 2017 and October 2018. Stereotactic 9-gauge vacuum-assisted biopsy was performed, acquiring twelve specimens per lesion. Calcification retrieval was assessed with individual specimen radiography. Each specimen was histologically analyzed in chronological order and findings were compared with the final histopathological result after assessment of all twelve specimens and with results of surgical excision. Cumulative diagnostic yield per specimen was calculated.

RESULTS

In total, 131 biopsy procedures were performed in 120 women (mean age 59 years). In 95% (95%CI 90%-98%) of the procedures a final histopathological diagnosis was reached after six specimens. After nine specimens the final biopsy diagnosis was established in all 131 cases. In the subgroup of 41 patients with a DCIS or invasive diagnosis at biopsy there were eight procedures (20%) where calcifications were retrieved before the diagnostic specimen was obtained. Underestimation of subsequent resection diagnosis occurred in six out of 30 excised lesions classified as DCIS (20%) and in one out of four excised high-risk lesions.

CONCLUSIONS

With six stereotactic 9-gauge vacuum-assisted biopsy specimens a final histopathological biopsy diagnosis could be established in 95% (95%CI 90%-98%) of the biopsy procedures. Taking nine 9-gauge specimens seems to be optimal. Ending the stereotactic vacuum-assisted breast biopsy procedure as soon as calcifications are retrieved may cause false negative results.