Metastatic Pleomorphic Lobular Carcinoma of the Breast to the Urinary Bladder: A Report of 10 Cases and Assessment of TRPS1 in the Differential Diagnosis With Plasmacytoid Urothelial Carcinoma.

Context.—: Metastatic pleomorphic lobular carcinoma (MPLC) to the bladder is rare and has considerable histologic and immunohistochemical overlap with plasmacytoid urothelial carcinoma (PUC).

Objective.

Immature natural killer cells promote progression of triple-negative breast cancer.

Natural killer (NK) cells are cytotoxic lymphocytes that accumulate within the tumor microenvironment and are generally considered to be antitumorigenic. Using single-cell RNA sequencing and functional analysis of multiple triple-negative breast cancer (TNBC) and basal tumor samples, we observed a unique subcluster of Socs3CD11bCD27 immature NK cells that were present only in TNBC samples. These tumor-infiltrating NK cells expressed a reduced cytotoxic granzyme signature and, in mice, were responsible for activating cancer stem cells through Wnt signaling.

Low to Intermediate (Borderline) Grade Breast Spindle Cell Lesions on Needle Biopsy: Diagnostic Approach and Clinical Management.

Spindle cell proliferations of the breast are a heterogeneous group of lesions ranging from benign or reactive lesions to aggressive malignant neoplasms. Diagnosis on core biopsy can be particularly challenging as lesions displaying different lineages associated with variable outcomes share overlapping morphologies (scar vs. fibromatosis-like metaplastic carcinoma) whereas individual entities can exhibit a large variety of appearances (myofibroblastoma).

HER2 Testing: Insights From Pathologists' Perspective on Technically Challenging HER2 FISH Cases.

Objective: College of American Pathologists and the American Society of Clinical Oncology guidelines provide straightforward criteria for HER2 interpretation in breast carcinomas; however, a subset of cases present unusual diagnostic dilemmas.

Materials And Methods: Ten challenging HER2 fluorescence in situ hybridization (FISH) cases were selected for analysis. The study included a variety of problematic cases such as those with discordant immunohistochemistry (IHC) and FISH results, cases with high intratumoral variability in HER2 copy number, a case with a highly amplified clone in 5% to 10% of the tumor sample, and a case with tumor cells containing tightly clumped HER2 signals.

HER2 Testing Characteristics Can Predict Residual Cancer Burden following Neoadjuvant Chemotherapy in HER2-Positive Breast Cancer.

Objectives: The response to HER2-targeted neoadjuvant chemotherapy (NAC) in HER2-positive (+) breast cancer can be quantified using residual cancer burden (RCB) pathologic evaluation to predict relapse free/overall survival. However, more information is needed to characterize the relationship between patterns of HER2 testing results and response to NAC. We evaluated clinicopathologic characteristics associated with RCB categories in HER2+ patients who underwent HER2-directed NAC.

Effects of Germline Pathogenic Variants, Cancer Subtypes, Tumor-related Characteristics, and Pregnancy-associated Diagnosis on Outcomes.

Background: Although breast cancer (BC) is uncommon in women age ≤ 35 years, women in this age group may have more aggressive cancer subtypes and high-risk pathogenic variants (HRPVs). Higher recurrence and mortality rates in young patients may be related to differences in tumor biology, pathologic mutation status, or treatment. The purpose of this study was to evaluate germline mutation status and other factors that affect recurrence-free survival (RFS) and overall survival (OS) in young women with BC.

Predictive value of breast magnetic resonance imaging in detecting mammographically occult contralateral breast cancer: Can we target women more likely to have contralateral breast cancer?

Background And Objectives: Preoperative breast magnetic resonance imaging (B-MRI) staging in newly diagnosed breast cancer increases detection of synchronous contralateral findings, but may result in false-positive outcomes. This study objective was to identify women more likely of having mammographically occult, MRI detected contralateral breast cancer (CBC).

Methods: We performed a retrospective review of patients who had preoperative B-MRI prior to surgery from 2010 to 2015 and collected patient imaging and clinicopathologic data.

Clinicopathologic analysis of a large series of microinvasive breast cancers.

Clinical management of microinvasive breast cancer (Tmic) remains controversial. Although metastases are infrequent in Tmic carcinoma patients, surgical treatment typically includes lymph node sampling. The objective of this study was to determine the rate and predictors of lymph node metastases, recurrence, and survival in a large series of Tmic breast carcinomas.

Surgical Outcomes of Lobular Neoplasia Diagnosed in Core Biopsy: Prospective Study of 316 Cases.

Background: Management recommendations for lobular neoplasia (LN) including lobular carcinoma-in-situ (LCIS) and atypical lobular hyperplasia (ALH) diagnosed in core biopsies (CB) are controversial. Our aim was to prospectively identify a subset of patients who do not require subsequent surgical excision (SE).

Patients And Methods: All patients diagnosed with LN on CB were enrolled and referred for SE.

Multinucleation is an objective feature useful in the diagnosis of pleomorphic lobular carcinoma in situ.

Objectives: Bi- and multinucleated (B/M) cells are present in a variety of tumors. We evaluated lobular carcinoma in situ (classic and pleomorphic types) and ductal carcinoma in situ (DCIS) to determine if this objective morphologic feature aids the differential diagnosis.

Methods: The number of B/M cells was recorded in pleomorphic lobular carcinoma in situ (PLCIS) (n = 20), classic lobular carcinoma in situ (CLCIS) (n = 26), and DCIS (n = 37).

Utility of Oncotype DX Risk Assessment in Patients With Invasive Lobular Carcinoma.

Introduction/background: Oncotype DX (Genomic Health, Redwood City, CA) uses reverse transcriptase polymerase chain reaction analysis to measure tumor gene expression for determining recurrence risk (RR) and guiding chemotherapy decisions for breast cancer patients. Invasive lobular carcinoma (ILC) is a histologic subtype that has not been the focus of prior studies validating Oncotype DX. The study purpose was to develop a model using histologic tumor characteristics to predict uniformly low Oncotype DX Recurrence Scores (RS) in ILC.

Office ductoscopy for surgical selection in women with pathologic nipple discharge.

Background: Pathologic nipple discharge (PND) is diagnosed clinically and managed by diagnostic duct excision (DDE). Mammary ductoscopy in the office setting may change this standard. We performed a prospective study to assess the utility of office ductoscopy for surgical selection in women with nipple discharge.

Lobular carcinoma in situ variants in breast cores: potential for misdiagnosis, upgrade rates at surgical excision, and practical implications.

Context: Differentiating ductal carcinoma in situ (DCIS) from lobular carcinoma in situ (LCIS) on core biopsy has important clinical implications. Lobular carcinoma in situ variants, including LCIS with necrosis and pleomorphic LCIS, share morphologic features with solid DCIS that may lead to misclassification.

Objectives: (1) To review all LCIS variants diagnosed in core biopsies at Northwestern University, Feinberg School of Medicine, and determine the frequency of misinterpretation of variant LCIS as solid DCIS in archival core biopsies, and (2) to determine the frequency of upgrade to invasive carcinoma or DCIS in the surgical excision.

Clinical roundtable monograph: a multidisciplinary approach to the use of oncotype DX in clinical practice.

Recently, recommendations for the use of the Oncotype DX assay in estrogen receptor-positive node-negative breast cancer patients were incorporated into guidelines from both the American Society of Clinical Oncology and the National Comprehensive Cancer Network. The Oncotype DX assay is a diagnostic test which measures changes in a set of 21 genes in order to predict the likelihood of disease recurrence and also to predict which patients are most likely to respond to chemotherapy. Oncotype DX has been available commercially since January 2004 and has been used for more than 85,000 patients.

Hypermethylated genes as biomarkers of cancer in women with pathologic nipple discharge.

Purpose: In a pilot study of women with pathologic nipple discharge (PND) undergoing ductoscopy, we tested quantitative assessment of gene promoter hypermethylation using quantitative multiplex methylation-specific PCR (QM-MSP) to enhance detection of duct carcinoma in situ (DCIS).

Experimental Design: Women with PND underwent ductoscopy; ducts with significant lesions were surgically resected (36 ducts in 33 women) and those with minimal findings were not (28 ducts in 16 women). QM-MSP was done on ductoscopy cell samples.

Paracortical axillary sentinel lymph node ectopic breast tissue.

Benign glandular inclusions in axillary lymph nodes are uncommon, and their presence in axillary sentinel lymph nodes is exceptionally rare. The possibility of over-staging due to misinterpretation of glandular inclusions as metastatic carcinoma is a concerning issue. We present a 54-year-old female with high grade ductal carcinoma in-situ undergoing simple mastectomy with sentinel lymph node biopsy.

Atypical lobular hyperplasia and classic lobular carcinoma in situ in core biopsy specimens: routine excision is not necessary.

Standardized recommendations for the management of lobular neoplasia in core biopsy specimens are not established. The aim of our study was to define morphologic features of lobular neoplasia in core biopsies that predict the finding of ductal carcinoma in situ or invasive carcinoma in the subsequent excisional specimen. We reviewed 333 cases of atypical lobular hyperplasia or lobular carcinoma in situ without ductal carcinoma in situ or invasive carcinoma diagnosed in core biopsies from 1996 to 2006.

Keratin immunohistochemistry does not contribute to correct lymph node staging in patients with invasive lobular carcinoma.

Studies suggest that immunohistochemistry improves rate of detecting sentinel lymph node metastases and is needed for adequate staging in invasive lobular carcinoma. Our study evaluates the use of cytokeratin immunohistochemistry in detecting sentinel lymph node metastases and its effect on staging patients with invasive lobular carcinoma. Material from 76 patients with invasive lobular carcinoma was reviewed.

HER2 in well differentiated breast cancer: is testing necessary?

Background: In addition to providing a timely and accurate diagnosis, pathologists routinely provide prognostic and predictive information to assist in the treatment of patients with invasive breast cancer. As our understanding of breast cancer at the molecular and genetic level improves, sophisticated new treatment options have become available to patients. The demonstrated improvements in disease-free and overall survival with the use of trastuzumab (Herceptin) has made HER2 testing a standard of care in the evaluation of patients with breast cancer.

Clinicopathologic features and long-term outcomes of 293 phyllodes tumors of the breast.

Background: Phyllodes tumors (PT) are rare fibroepithelial neoplasms of the breast with unpredictable behavior. We reviewed our single institution experience with PT over 51 years to identify factors predictive of local recurrence (LR) and metastasis.

Methods: From 1954 to 2005, a total of 352 cases of PT were identified; 293 had follow-up.

Giant apocrine hidradenoma of the breast.

We report a case of a 26-year-old woman with an 8.0-cm tumor of the left breast. The tumor was clinically and radiologically suspicious for malignancy.

Postirradiation morphea in a breast cancer patient.

We present the case of a 52-year-old woman who underwent lumpectomy and radiation therapy for breast carcinoma and 2 years later presented with changes limited to the breast radiation field including hyperpigmentation, retraction, and skin thickening. These clinical features, along with pathologic findings, were diagnostic of postirradiation morphea. It is important to be aware of this rare complication of radiation therapy because it clinically presents with symptoms mimicking malignancy and may be misinterpreted as recurrent carcinoma or even angiosarcoma.

Occult micrometastases in axillary lymph nodes predict subsequent distant metastases in stage I breast cancer: a case-control study with 15-year follow-up.

Background: The prognostic significance of occult axillary metastases was evaluated in patients with stage I breast cancer.

Methods: Ninety-six patients with pT1 breast carcinoma who underwent axillary lymph node dissection had negative nodes in routine microscopic examination. Forty-eight patients developed distant metastases within 15 years after surgery (M group) and are compared to 48 age-matched patients who were disease-free for 15 years (NM group).