Indeterminate (B3) Breast Lesions and the Ongoing Role of Diagnostic Open Biopsy

Introduction. Due to their uncertain malignant potential, indeterminate breast lesions on core needle biopsy (CNB) require diagnostic open biopsy (DOB). This study evaluated DOB results given largely benign pathology. Lesions included are atypical papilloma, atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), and radial scar/complex sclerosing lesions (RS/CSL). Methodology. A retrospective audit from 2010 to 2017 analysed patients with a screen-detected suspicious lesion and indeterminate (B3) CNB diagnosis. Primary outcome was the malignancy upgrade rate, with secondary evaluation of patient factors predictive of malignancy including age, symptoms, mammogram characteristics, lesion size, biopsy method, and past and family history. Results. 152 patients (median age 57 years) were included, with atypical papillomas being the largest subgroup (44.7%). On DOB histology, 99.34% were benign, resulting in a 0.66% malignancy upgrade rate. Patient characteristic analysis identified 86.84% of B3 lesions were in patients greater than 50 years old. 90.13% were asymptomatic, whilst 98.68% and 72.37% had a negative past and family history. Majority 46.71% of lesions had the mammogram characteristic of being a mass. However, with 57.89% of the lesion imaging size less than 4 mm, a corresponding 60.5% of core needle biopsies were performed stereotactically. The small malignant subgroup limited predictive factor evaluation. Conclusion. Albeit a low 0.66% malignancy upgrade rate in B3 lesions, no statistically significant patient predictive factors were identified. Until predictive factors and further assessment of vacuum-assisted excision (VAE) techniques evolve, DOB remains the standard of care.

High-risk lesions of the breast: concurrent diagnostic tools and management recommendations

Breast lesions with uncertain malignant behavior, also known as high-risk or B3 lesions, are composed of a variety of pathologies with differing risks of associated malignancy. While open excision was previously preferred to manage all high-risk lesions, tailored management has been increasingly favored to reduce overtreatment and spare patients from unnecessary anxiety or high healthcare costs associated with surgical excision. The purpose of this work is to provide the reader with an accurate overview focused on the main high-risk lesions of the breast: atypical intraductal epithelial proliferation (atypical ductal hyperplasia), lobular neoplasia (including the subcategories lobular carcinoma in situ and atypical lobular hyperplasia), flat epithelial atypia, radial scar and papillary lesions, and phyllodes tumor. Beyond merely presenting the radiological aspects of these lesions and the recent literature, information about their potential upgrade rates is discussed in order to provide a useful guide for appropriate clinical management while avoiding the risks of unnecessary surgical intervention (overtreatment).

Radial Scar: a management dilemma

Radial scar (RS) or complex sclerosing lesions (CSL) if > 10 mm is a benign lesion with an increasing incidence of diagnosis (ranging from 0.6 to 3.7%) and represents a challenge both for radiologists and for pathologists. The digital mammography and digital breast tomosynthesis appearances of RS are well documented, according to the literature. On ultrasound, variable aspects can be detected. Magnetic resonance imaging contribution to differential diagnosis with carcinoma is growing. As for the management, a vacuum-assisted biopsy (VAB) with large core is recommended after a percutaneous diagnosis of RS due to potential sampling error. According to the recent International Consensus Conference, a RS/CSL lesion, which is visible on imaging, should undergo therapeutic excision with VAB. Thereafter, surveillance is justified. The aim of this review is to provide a practical guide for the recognition of RS on imaging, illustrating radiological findings according to the most recent literature, and to delineate the management strategies that follow.

Significance of adenosquamous proliferation in breast lesions

Adenosquamous proliferation (ASP), characterised by ductal structures with a dual glandular and squamous phenotype within desmoplastic stroma, is essentially a hallmark of various sclerosing lesions of the breast (SL) and breast lesions with sclerosis (BLWS), not including sclerosing adenosis. In radial scar/complex sclerosing lesion (RS/CSL), clonality has been previously demonstrated in microdissected ASP. SL/BLWS encompass a diverse range of pathological entities that historically have an equally diverse list of names, often for histologically alike or identical lesions at different anatomical locations. In common they are comprised of one or more components of fibrocystic or proliferative breast disease and papillomata, which become distorted and even obliterated by a sclerosing process that appears to be associated with and/or secondary to ASP, which in an individual lesion may be inconspicuous at the time of biopsy. The histological overlap of various SL/BLWS with RS/CSL, in which a nidus containing ASP is pathognomonic of early lesions, also supports a common element of ASP across various SL/BLWS. SL/BLWS show an interesting association with low-grade metaplastic carcinoma, particularly low-grade adenosquamous carcinoma (LGASC) with which, they appear to form a histological and possible biological spectrum because ASP and LGASC share similar histological and immunophenotypical characteristics. The presentation of ASP in various SL/BLWS will be discussed.

Histologic Correlation of Breast Biopsies Presenting as Non-Mass Enhancing Lesions on Magnetic Resonance Imaging: A Contemporary Single Institutional Series

Introduction/Objective Non-mass enhancement (NME) in breast tissue is an area of enhancement on MRI that appears distinct from background breast parenchyma, but lacks definitive features of a mass. NME is characterized by its internal enhancement pattern and distribution, and can represent benign, high risk, or malignant pathology. Given this considerable overlap, a core biopsy is often necessary for diagnosis and management. We aimed to elucidate the most frequent histologic findings found on breast biopsies for MRI NME. Methods Using our institutional database we identified 70 female patients with high risk status for breast cancer with MRI screen detected NME (BIRADS-4-suspicious for malignancy) that underwent subsequent biopsy procedure during the period of 01/2016-12/2017. Primary pathologic diagnoses were subcategorized as follows: malignant, atypical, benign mass-like lesions, fibrocystic changes (proliferative, nonproliferative), or “other” primary diagnoses. Results The median age of patients was 48 years (range: 22-76 years). Of the 70 patients, 66 underwent MRI-guided core biopsy, 3 underwent ultrasound-guided core biopsy and 1 underwent excisional biopsy. The primary diagnosis was analyzed. Of these 70 cases, 8 (11.4%) were malignant (7 with ductal carcinoma in situ and 1 with invasive ductal carcinoma), 1 (1.4%) had atypical lobular hyperplasia, and the remaining 61 (87.1%) showed benign findings (36 with fibrocystic changes (FCC), 22 benign mass-like lesions, 3 with other non-specific findings). The FCC were subcategorized as proliferative (usual ductal hyperplasia, columnar cell change, incidental radial scar, incidental intraductal papilloma, sclerosing adenosis, focal pseudoangiomatous stromal hyperplasia (PASH)) or nonprolifeative (stromal fibrosis, duct ectasia, apocrine metaplasia). Majority (61.1%) of FCC were both proliferative and nonproliferative, 22.2% proliferative only and 16.7% nonproliferative only. Benign mass-like lesions included PASH (45.4%), fibroadenomatoid nodule (22.7%), fat necrosis (18.2 %) and remaining had the diagnosis of clustered apocrine cysts, papillomatosis, and radial sclerosing lesion. Conclusion Less than a third of cases showed malignant findings and more than two-third of cases showed benign findings with a high rate of detection of proliferative lesions and PASH.

Breast MRI Does Not Help Differentiating Radial Scar With and Without Associated Atypia or Malignancy

Purpose: To review breast magnetic resonance imaging (MRI) features of radial scar (RS) with and without associated atypia/malignancy. Methods: Twenty-eight (mean age 56.8) patients diagnosed with 30 biopsy-proven RS (n = 25, ultrasound-guided 14-gauge, n = 5, stereotactically guided 9-gauge) subsequently underwent breast MRI followed by surgery. Magnetic resonance imaging protocol included axial T1, axial fat sat T2, and postgadolinium in axial and sagittal planes. Two radiologists reviewed the mammographic and MRI findings in consensus according to the Breast Imaging Reporting and Data System lexicon. Results: Of the 30 RSs excised surgically, 14 (14/30, 47.7%) were not associated with atypia/malignancy while atypia/malignancy was found in 16 (16/30, 53.3%) RSs. Three (3/30, 10%) RS lesions did not enhance on dynamic MR. Mean lesion size on MRI was 1.4 cm (range, 0.5-5 cm). Seventeen (17/30, 56.7%) lesions presented as nonmass enhancement and 9 (9/30, 30%) as masses. Nonmass lesions showed focal distribution (13/17, 76.5%) and heterogeneous enhancement (15/17, 88.2%). Masses showed irregular shape and margins (6/9, 67%) and heterogeneous enhancement (8/9, 89%). Multivariate analysis did not show any significant difference in MRI presentation between RS only and RS associated with atypia/malignancy. Conclusion: Breast MRI does not help differentiate between RS with or without associated atypia/malignancy.

“Harms” Associated with Breast Cancer Screening and Reliability of Frozen Section in Older Women: In the Case of an 80 Year Old Woman

The objective of this paper is to present a rare case with negative final histologic examination despite abnormal findings of all previous exams indicating breast cancer in an 80 year old woman. Mammographic and magnetic resonance imaging findings were concordant with the frozen section biopsy result of DCIS. However, the final histologic diagnosis was radial scar (benign breast lesion that can radiologically mimic malignancy). As a conclusion, abnormal mammographic and magnetic resonance imaging findings with positive for DCIS frozen section reports are not always confirmed in the final histologic examination. Furthermore, considering that screening does not seem to be associated with a reduction in mortality due to breast cancer after the age of 75, breast cancer screening could be individualized in this age group.