The Critical Role of Breast Specimen Gross Evaluation for Optimal Personalized Cancer Care

Pathologic Features of Malignancies Presenting as Asymmetry on Mammography

The majority of breast cancers have a solid tumor growth pattern and are seen on mammography as dense masses with defined borders. Cancers detected as asymmetry are rare, and little has been published about their pathologic features. These cancers do not form discrete masses, and a border is not evident. This retrospective case series was undertaken to identify malignancies presenting as asymmetry, to describe their histologic and biologic features and to correlate these features with the mammographic appearance. During the 7.5 years of the study, 18,419 coreneedle biopsies were performed and 42 cases of malignancy presenting as asymmetry were diagnosed (0.2%). The majority were invasive carcinomas (30% or 71%), followed by ductal carcinoma in situ (9% or 21%) and lymphoma (3% or 7%). The invasive carcinomas could be divided into 3 groups: very small unifocal (T1a) carcinomas, larger unifocal carcinomas, and cases with multiple foci of invasion. The latter group had a higher rate of lymph node metastases and more stage III cancers. The invasive carcinomas were predominantly of special histologic types and associated with a minimal stromal response. In contrast, the cases of ductal carcinoma in situ tended to be of higher grade and elicited periductal fibrosis, which likely contributed to the increased density seen on mammography. Although most of the invasive carcinomas were of favorable biologic type (97%) and were stage I (67%), triple-negative carcinomas and stage III carcinomas were also detected. When evaluating core needle biopsies performed for asymmetry, pathologists should be aware that these cancers can have a subtle infiltrative appearance with little or no desmoplastic response, mirroring their appearance by imaging.

Resection Ratios and Tumor Eccentricity in Breast-Conserving Surgery Specimens for Surgical Accuracy Assessment

This study aims to evaluate several defined specimen parameters that would allow to determine the surgical accuracy of breast-conserving surgeries (BCS) in a representative population of patients. These specimen parameters could be used to compare surgical accuracy when using novel technologies for intra-operative BCS guidance in the future. Different specimen parameters were determined among 100 BCS patients, including the ratio of specimen volume to tumor volume (resection ratio) with different optimal margin widths (0 mm, 1 mm, 2 mm, and 10 mm). Furthermore, the tumor eccentricity [maximum tumor-margin distance - minimum tumor-margin distance] and the relative tumor eccentricity [tumor eccentricity ÷ pathological tumor diameter] were determined. Different patient subgroups were compared using Wilcoxon rank sum tests. When using a surgical margin width of 0 mm, 1 mm, 2 mm, and 10 mm, on average, 19.16 (IQR 44.36), 9.94 (IQR 18.09), 6.06 (IQR 9.69) and 1.35 (IQR 1.78) times the ideal resection volume was excised, respectively. The median tumor eccentricity among the entire patient population was 11.29 mm (SD = 3.99) and the median relative tumor eccentricity was 0.66 (SD = 2.22). Resection ratios based on different optimal margin widths (0 mm, 1 mm, 2 mm, and 10 mm) and the (relative) tumor eccentricity could be valuable outcome measures to evaluate the surgical accuracy of novel technologies for intra-operative BCS guidance.

The Use of Optical Coherence Tomography for Gross Examination and Sampling of Fixed Breast Specimens: A Pilot Study

Thorough gross examination of breast cancer specimens is critical in order to sample relevant portions for subsequent microscopic examination. This task would benefit from an imaging tool which permits targeted and accurate block selection. Optical coherence tomography (OCT) is a non-destructive imaging technique that visualizes tissue architecture and has the potential to be an adjunct at the gross bench. Our objectives were: (1) to familiarize pathologists with the appearance of breast tissue entities on OCT; and (2) to evaluate the yield and quality of OCT images of unprocessed, formalin-fixed breast specimens for the purpose of learning and establishment of an OCT–histopathology library. Methods: Firstly, 175 samples from 40 formalin-fixed, unprocessed breast specimens with residual tissue after final diagnosis were imaged with OCT and then processed into histology slides. Histology findings were correlated with features on OCT. Results: Residual malignancy was seen in 30% of tissue samples. Corresponding OCT images demonstrated that tumor can be differentiated from fibrous stroma, based on features such as irregular boundary, heterogeneous texture and reduced penetration depth. Ductal carcinoma in situ can be subtle, and it is made more recognizable by the presence of comedo necrosis and calcifications. OCT features of benign and malignant breast entities were compiled in a granular but user-friendly reference tool. Conclusion: OCT images of fixed breast tissue were of sufficient quality to reproduce features of breast entities previously described in fresh tissue specimens. Our findings support the use of readily available unprocessed, fixed breast specimens for the establishment of an OCT–histopathology library.