The Impact of Tumor Size in Breast Needle Biopsy Material on Final Pathologic Size and Tumor Stage: A Detailed Analysis of 222 Consecutive Cases

Ultrasound-guided breast biopsy using an adapted automated cone-based ultrasound scanner: a feasibility study

BACKGROUND

Among available breast biopsy techniques, ultrasound (US)-guided biopsy is preferable because it is relatively inexpensive and provides live imaging feedback. The availability of magnetic resonance imaging (MRI)-3D US image fusion would facilitate US-guided biopsy even for US occult lesions to reduce the need for expensive and time-consuming MRI-guided biopsy. In this paper, we propose a novel Automated Cone-based Breast Ultrasound Scanning and Biopsy System (ACBUS-BS) to scan and biopsy breasts of women in prone position. It is based on a previously developed system, called ACBUS, that facilitates MRI-3D US image fusion imaging of the breast employing a conical container filled with coupling medium.

PURPOSE

The purpose of this study was to introduce the ABCUS-BS system and demonstrate its feasibility for biopsy of US occult lesions.

METHOD

The biopsy procedure with the ACBUS-BS comprises four steps: target localization, positioning, preparation, and biopsy. The biopsy outcome can be impacted by 5 types of errors: due to lesion segmentation, MRI-3D US registration, navigation, lesion tracking during repositioning, and US inaccuracy (due to sound speed difference between the sample and the one used for image reconstruction). For the quantification, we use a soft custom-made polyvinyl alcohol phantom (PVA) containing eight lesions (three US-occult and five US-visible lesions of 10 mm in diameter) and a commercial breast mimicking phantom with a median stiffness of 7.6 and 28 kPa, respectively. Errors of all types were quantified using the custom-made phantom. The error due to lesion tracking was also quantified with the commercial phantom. Finally, the technology was validated by biopsying the custom-made phantom and comparing the size of the biopsied material to the original lesion size. The average size of the 10-mm-sized lesions in the biopsy specimen was 7.00 ± 0.92 mm (6.33 ± 1.16 mm for US occult lesions, and 7.40 ± 0.55 mm for US-visible lesions).

RESULTS

For the PVA phantom, the errors due to registration, navigation, lesion tracking during repositioning, and US inaccuracy were 1.33, 0.30, 2.12, and 0.55 mm. The total error was 4.01 mm. For the commercial phantom, the error due to lesion tracking was estimated at 1.10 mm, and the total error was 4.11 mm. Given these results, the system is expected to successfully biopsy lesions larger than 8.22 mm in diameter. Patient studies will have to be carried out to confirm this in vivo.

CONCLUSION

The ACBUS-BS facilitates US-guided biopsy of lesions detected in pre-MRI and therefore might offer a low-cost alternative to MRI-guided biopsy. We demonstrated the feasibility of the approach by successfully taking biopsies of five US-visible and three US-occult lesions embedded in a soft breast-shaped phantom.

Measuring Invasive Breast Carcinoma on Core Biopsy: Is it Necessary?: An Analysis of Ultrasound, Mammotome, and Magnetic Resonance Imaging-Guided Core Biopsies

CONTEXT.—

Pathologic tumor size is significant in the treatment of breast carcinoma and is routinely measured on excision.

OBJECTIVE.—

To analyze the need for measuring size of invasive mammary carcinoma on biopsy.

DESIGN.—

Nine hundred twenty-two cases of invasive carcinoma whose size was measured (greatest linear measurement) on biopsy and excision was correlated, including imaging when available (110 cases).

RESULTS.—

Patient mean age was 62 years. Most (90%; 830 of 922) carcinomas were ductal and sampled by ultrasound and graded as follows: well, 13% (113 of 922); moderately, 58% (532 of 922), and poorly differentiated, 28% (258 of 922); 19 microinvasive not graded. Tumor mean size was 7.5 mm on biopsy and 14.4 mm on excision. Biopsy modality was as follows: ultrasound, 7.8 mm (92%, 844 of 922); mammotome, 3.3 mm (7%, 65 of 922); and magnetic resonance imaging, 5.9 mm (1%, 13 of 922). Size comparison on biopsy versus excision was biopsy > excision: 8% (72 of 922), biopsy = excision: 10% (95 of 922), and biopsy < excision: 82% (755 of 922). Half (36 of 72) of the biopsy > excision tumors were less than 5 mm, 96% (726 of 755) of biopsy < excision tumors were greater than 5 mm, while those equal on both were predominantly (88%, 84 of 95) less than 10 mm, 20% (19 of 95) of which were microinvasive. Stage changed in 600 cases, staging based on excision in 581 (63%), and staging based on biopsy in 19 (2%). Radiologic-pathologic correlation (n = 110) showed perfect concordance in 11 (10%), 83 (75%) were ±1 to 2 mm and 16 (15%) were ± more than 3 mm. Difference between the biopsy and excision ranged from a lower limit of 1.3 mm for T1a tumors to 18 mm for T2.

CONCLUSIONS.—

While most carcinomas are larger on excision, 18% (167 of 922) are larger or equal on biopsy. Factors predictive of biopsy > excision tumors include stage 1 tumors (P < .001), especially less than 5 mm, and sampled by mammotome. We recommend measuring invasive carcinoma on biopsy and excision.

Differences in immunohistochemistry utilization by general and breast subspecialty pathologists at a large academic institution

OBJECTIVES

Immunohistochemistry (IHC) can be a useful adjunct in diagnostic breast pathology, but best practices have not been clearly established. We sought to compare the patterns of p63 utilization between general pathologists (GP) and subspecialized breast pathologists (BP), analyze diagnostic discrepancy rates, and identify types of lesions requiring immunohistochemistry.

METHODS

The pathology database was searched over 6-year period to identify breast needle core biopsy cases utilizing p63 and subsequent excision results.

RESULTS

P63 was ordered more frequently by BP (2.3% of cores) compared to GP (1.1% of cores, p = 0.0005). The most frequent utilization of p63 by GP for benign lesions (44.0%) followed by invasive carcinomas (36.0%) while BP most frequently ordered p63 on invasive carcinomas (49.5%) and DCIS (26.6%).

CONCLUSIONS

While IHC use may be thought to be most helpful to those with less experience or knowledge in breast pathology, these results suggest that utilization is increased with subspecialty training.

Invasive Breast Carcinoma Tumor Size on Core Needle Biopsy: Analysis of Practice Patterns and Effect on Final Pathologic Tumor Stage

INTRODUCTION

In the absence of nodal metastasis, pathologic tumor (pT) size remains one of the most important factors in adjuvant treatment decisions and patient prognosis in breast cancer. The aim of this study was to evaluate the effect of core needle biopsy (CNB) tumor size on final pT stage.

MATERIALS AND METHODS

Our information system was searched to identify all patients who underwent excisional procedures for invasive breast carcinoma from January 1^, 2014 to December 31, 2015. The tumor size on CNB and final excision, the number of cases in which the CNB size was larger, and the percentage of cases in which using the CNB tumor size changed the final pT stage were recorded.

RESULTS

From 1380 primary breast excisions/mastectomies, a total of 870 cases were included. In 82 (9.4%) the CNB tumor size was larger (63 of 82 cases) or no residual tumor was identified on excision (19 of 82 cases). From these 82 cases, 40 (48.7%) were properly staged on the basis of CNB tumor size, 16 (19.5%) were not staged, and 26 (31.7%) were staged using the final excision tumor size. Change in stage occurred in 7 of these 26 patients.

CONCLUSION

Our study revealed that in most cases, the largest tumor size is found in the excision/mastectomy specimen. However, in 9.4% (82 of 870), the CNB contains the most accurate tumor size for pT staging. On the basis of our results, including the largest linear tumor extent on the CNB report is recommended.

Tumor Size in Breast Carcinoma: Gross Measurement Is Important!

Introduction. The staging of breast carcinoma is mainly dependent on tumor size and lymph node status. Small increments in tumor size upstage the patient. An accurate determination of the tumor size is therefore critically important. Although the final staging is based on microscopic size, pathologists rely on gross measurements in a considerable number of cases. Methods. We investigated the concordance between gross and microscopic measurements of breast carcinoma as well as factors affecting this concordance. This study is a retrospective review of surgical pathology reports of invasive breast carcinomas. Data were collected for 411 cases. Concordance was defined as a size difference within ±2 mm. Results. Gross and microscopic sizes were identical in 33.1% of cases. Gross and microscopic size difference was within ±2 mm in 56% of cases. Despite the size difference, stage classification ended up being the same in 68.6% of cases. Tumor stage was over estimated by gross measurement in 17.0% of cases and underestimated in 14.4% of cases. The concordance was significantly higher for those tumors in which final pathologic tumor (pT) size was greater than 2 cm (≥pT2) as compared with those less than or equal to 2 cm (≤pT1; P < .0001). A higher proportion of mastectomy specimens (61.4%) were concordant as compared with lumpectomy specimens (52.1%). Conclusion. Gross and microscopic tumor sizes were concordant in 56% of cases. Stage classification based on gross and microscopic tumor size was different in nearly one third (31.4%) of cases. Gross tumor size is critically important in accurate staging at least in cases where tumor size cannot be confirmed microscopically.

Correlation between invasive mammary carcinoma grade and size in ultrasound-guided core needle biopsy and subsequent surgical excision

The purpose of this study was to correlate the histologic grade, mitotic rate and size of invasive mammary carcinomas (IMC) on ultrasound (US) core needle biopsy (CNB) and the follow-up excision (FUE). The underestimation and overestimation of the grades by CNB were 11% and 8%. CNBs were more specific for grade 3 tumors. Tumors >10 mm by US examination showed greater concordance in grades. The size in the FUE was the best determinant of pT followed by US examination. The extent of IMC on CNB was larger than FUE in 8% resulting in pT upstaging in 3% of cases.

Complexities and challenges in the pathologic assessment of size (T) of invasive breast carcinoma

Size (the "T" in the TNM System) of invasive breast carcinoma is a proven independent prognostic factor; however, its accurate determination can be challenging. The purpose of this review is to discuss the complexities inherent in determining "T"-including those encountered in the clinical measurement ("cT", ie, physical and radiologic assessment) as well as pathologic determination (pT) of invasive breast carcinomas. Pathologic estimation of tumor size, macroscopic, as well as microscopic, can be problematic due to the complexity of multiple situations, seeming confusion regarding staging guidelines, and interobserver variation in interpretation. Additional problematic scenarios in determination of "T" include those incurred in excisions performed after the performance of needle core biopsies, and in cases wherein there are multiple foci of invasive carcinoma, as well as in carcinomas status post-neoadjuvant chemotherapy. It can also be difficult to determine "T" in certain types of invasive carcinoma, particularly those of the lobular type. In this communication, some of the complexities and challenges in determing "T" are discussed, and modest suggestions are offered to assist in optimizing such assessments.

The clinical use of a P63/cytokeratin7/18/cytokeratin5/14 antibody cocktail in diagnostic breast pathology

An antibody cocktail directed against p63, cytokeratin (CK)5/14, and CK7/18 is reported to be useful in distinguishing noninvasive from invasive breast lesions and for the characterization of intraductal epithelial proliferations. However, limited studies evaluate its use in clinical practice. A retrospective review of breast material at a university medical center identified cases that were immunostained with the above antibody cocktail. Additional p63 immunostaining alone was performed to further determine the utility of the antibody cocktail in the evaluation of invasion. Of 50 breast cases identified, the antibody cocktail was used to confirm or exclude invasion in 44 (88%). Twenty-two (50%) of these had easily identifiable p63/CK5/14-positive myoepithelial cells, whereas the remainder lacked such staining, confirming the diagnosis of invasive carcinoma. In 27 cases with available diagnostic material for additional p63 immunostaining, the cocktail better highlighted myoepithelial cells by staining nuclei and cytoplasm. Easier identification of invasion was also facilitated by CK7/18 expression in invasive foci, especially those composed of single cells. Ten cases were immunostained to help determine the nature of an intraductal proliferation. The cocktail demonstrated a mosaic staining pattern of both CK7/18- and CK5/14-positive epithelial cells in 3 (30%) cases consistent with usual hyperplasia; homogenous CK7/18 expression in the remaining cases supported the diagnosis of atypical ductal hyperplasia or carcinoma in situ. In summary, the p63/CK7/18/CK5/14 cocktail stain appears to be a useful tool in diagnostic breast pathology, in the evaluation of possible invasion, particularly in the setting of minute foci of invasion as well as in epithelial proliferations.