Clinicopathologic Features of Breast Tumors in Germline TP53 Variant-Associated Li-Fraumeni Syndrome.

We present one of the largest cohorts of TP53-pathogenic germline variants (PGVs) associated with patients with Li-Fraumeni syndrome (n = 82) with breast tumors (19 to 76 y; median age: 35). Most had missense variants (77%), followed by large gene rearrangements (LGRs; 12%), truncating (6%), and splice-site (5%) variants. Twenty-one unique germline missense variants were found, with hotspots at codons 175, 181, 245, 248, 273, 334, and 337.

Time to Treatment Initiation for Breast Cancer During the 2020 COVID-19 Pandemic.

Purpose: The COVID-19 pandemic has posed significant pressures on healthcare systems, raising concern that related care delays will result in excess cancer-related deaths. Because data regarding the impact on patients with breast cancer are urgently needed, we aimed to provide a preliminary estimate of the impact of COVID-19 on time to treatment initiation (TTI) for patients newly diagnosed with breast cancer cared for at a large academic center.

Methods: We conducted a retrospective study of patients with newly diagnosed early-stage breast cancer between January 1, 2020, and May 15, 2020, a time period during which care was affected by COVID-19, and an unaffected cohort diagnosed between January 1, 2018 and May 15, 2018.

Iatrogenic issues in breast pathology.

Modern breast imaging techniques include digital mammography, 3-dimensional tomography, high-resolution ultrasound, and magnetic resonance imaging. Each of these has enabled the diagnosis of ever smaller, largely non-palpable lesions, not all of which require surgery. As these techniques evolved, so too did methods of accurately targeting and sampling the lesions, necessitating methods to mark the areas should surgical localization be needed.

Adenomyoepitheliomas of the Breast Frequently Harbor Recurrent Hotspot Mutations in PIK3-AKT Pathway-related Genes and a Subset Show Genetic Similarity to Salivary Gland Epithelial-Myoepithelial Carcinoma.

Adenomyoepitheliomas (AME) of the breast and epithelial-myoepithelial carcinomas (EMCs) of salivary gland are morphologically similar tumors defined by the presence of a biphasic population of ductal epithelial elements mixed with myoepithelial cells. We sought to explore the molecular profile of AMEs and determine whether they might also share the PLAG1, HMGA2, and HRAS alterations seen in EMCs. Tumor tissue from 19 AMEs was sequenced and analyzed using Ion AmpliSeq Cancer Hotspot Panel v2 covering ∼2800 COSMIC mutations across 50 cancer-related genes.

Microglandular Adenosis: A Possible Non-Obligate Precursor to Breast Carcinoma With Potential to Either Luminal-Type or Basal-Type Differentiation.

Microglandular adenosis (MGA) of the breast is exceedingly rare, with only a few case reports and series published to date. Previous studies have elegantly demonstrated the progression of benign MGA to atypical MGA to MGA-in situ carcinoma to invasive carcinoma and therefore suggest MGA as a possible non-obligate precursor lesion to a subset of breast carcinomas. Immunohistochemically, MGA is negative for estrogen receptor (ER), progesterone receptor (PR), and HER2-neu oncoprotein expression, and carcinomas arising in the setting of MGA are often reported to be triple negative.

Evaluation of Biomarkers in Multiple Ipsilateral Synchronous Invasive Breast Carcinomas.

Context.—: The College of American Pathologists guidelines recommend testing additional tumor foci in multifocal invasive breast carcinomas for the biomarkers estrogen receptor (ER), progesterone receptor, and HER2 only if the carcinomas show different morphologies or grades.

Objective.

MYB rearrangement and immunohistochemical expression in adenomyoepithelioma of the breast: a comparison with adenoid cystic carcinoma.

Aims: Adenomyoepithelioma (AME) and adenoid cystic carcinoma (ACC) of the breast have been noted to occur simultaneously, raising the possibility that AME may represent a related or precursor lesion to ACC. ACC frequently harbours genetic rearrangement of the MYB gene. We sought to clarify the relationship between AME and ACC by comparing their rates of MYB expression by IHC and MYB rearrangement by FISH.

Mucinous Cystadenocarcinoma of the Breast: Report of 2 Cases Including One With Long-Term Local Recurrence.

Primary mucinous cystadenocarcinoma (MCA) of breast is an exceedingly rare tumor with histologic resemblance to MCA arising in ovary, pancreas, and gastrointestinal tract. In this article, we present 2 additional cases of MCA of breast, one highlighting the diagnostic challenges of a rare entity that may potentially lead to unnecessary chemotherapy and the second case presenting with recurrence after 8 years of primary surgical excision defying the indolent behavior reported in the literature. To our knowledge, this is the first reported instance of such behavior.

Observation versus excision of lobular neoplasia on core needle biopsy of the breast.

Purpose: Controversy surrounds management of lobular neoplasia (LN), [atypical lobular hyperplasia (ALH) or lobular carcinoma in situ (LCIS)], diagnosed on core needle biopsy (CNB). Retrospective series of pure ALH and LCIS reported "upgrade" rate to DCIS or invasive cancer in 0-40%. Few reports document radiologic/pathologic correlation to exclude cases of discordance that are the likely source of most upgrades, and there is minimal data on outcomes with follow-up imaging and clinical surveillance.

Iatrogenically false positive sentinel lymph nodes in breast cancer: Methods of recognition and evaluation.

With the introduction of sentinel lymph node (SLN) biopsy as a standard procedure for staging clinically node negative breast cancer patients, meticulous pathologic evaluation of SLNs by serial sections and/or immunohistochemistry for cytokeratins has become commonplace in order to detect small volume metastases (isolated tumor cells and micrometastases). This practice has also brought to the fore the concept of iatrogenically false positive sentinel nodes secondary to epithelial displacement produced largely by preoperative needling procedures. While this concept is well described in the clinical and pathologic literature, it is, in our experience, still under-recognized, with such lymph nodes frequently incorrectly diagnosed as harboring true metastases, possibly resulting in unwarranted further surgery and/or chemotherapy.

The Impact of 2013 Updated ASCO/CAP HER2 Guidelines on the Diagnosis and Management of Invasive Breast Cancer: A Single-Center Study of 1739 Cases.

Background: The purpose of this study was to determine the impact of revised ASCO/CAP 2013 HER2 guidelines on the clinical practice of pathologists and oncologists.

Materials And Methods: Retrospective analysis of 1739 patients with invasive breast carcinoma who underwent reflex HER2 (fluorescence in situ hybridization [FISH]) testing, using both 2007 and 2013 guidelines (2007-2014).

Results: Using 2013 guidelines, 255 (15%; 95% confidence interval [CI], 13%-16%) cases were classified as HER2 as opposed to 186 (11%; 95% CI, 9%-12%) by 2007 guidelines (odds ratio [OR] 1.

Correlation of Oncotype DX Recurrence Score with Histomorphology and Immunohistochemistry in over 500 Patients.

Oncotype Dx is used to determine the recurrence risk (RR) in patients with estrogen receptor positive (ER+) and lymph node negative (LN-) breast cancer. The RR is divided into low (0-17), intermediate (18-30), and high (31) to predict chemotherapy benefit. Our goal was to determine the association between histomorphology, immunohistochemistry, and RR.

Changes in Pathological Complete Response Rates after Neoadjuvant Chemotherapy for Breast Carcinoma over Five Years.

Historically, neoadjuvant chemotherapy (NACT) was extrapolated from adjuvant regimens. Dual HER2 blockade and the introduction of carboplatin for triple negative breast cancers (TNBC) emerged by December 2013 and have improved pathological complete response (pCR) rates. The objective of this study was to assess the pCR rates before and after the introduction of these new neoadjuvant regimens.

Phyllodes tumours of the breast: a consensus review.

Phyllodes tumours constitute an uncommon but complex group of mammary fibroepithelial lesions. Accurate and reproducible grading of these tumours has long been challenging, owing to the need to assess multiple stratified histological parameters, which may be weighted differently by individual pathologists. Distinction of benign phyllodes tumours from cellular fibroadenomas is fraught with difficulty, due to overlapping microscopic features.

The clinical significance of internal mammary lymph node (IMLN) biopsy during autologous reconstruction in breast cancer patients.

The clinical significance of IMLN metastases in breast cancer is controversial. Although IMLN status is an integral part of current AJCC staging of breast cancer, the elective sampling of IMLN is not part of routine surgery for breast cancer. The purpose of this study was to determine the incidence of IMLN metastases, associated risk factors if any, and its impact on further management and outcome.

A unique presentation of occult primary breast cancer with a review of the literature.

We are reporting a case of a 34-year-old woman with occult primary breast cancer discovered after initially presenting with neurological symptoms. She was successfully treated with neoadjuvant chemotherapy followed by definitive axillary lymph node dissection and ipsilateral whole breast radiotherapy. The case presented is unique due to the rarity of occult primary breast cancer, especially in light of her initial confounding neurological signs and symptoms, which highlights the importance of careful staging.

Novel Hormone Receptors Present in Apocrine Cystadenoma of the Eyelid.

A 53-year-old woman presented with an apocrine cystadenoma of the right upper eyelid. Histologic examination revealed proliferating epithelial cells with apocrine snouts and occasional mitotic figures. Immunohistochemical analysis revealed a Ki-67 index of 15% and positive staining for synaptophysin, chromogranin, estrogen receptor, progesterone receptor, gross cystic disease fluid protein (GCDFP)-15, and mammoglobin.

Evolution of sentinel lymph node biopsy in breast cancer, in and out of vogue?

Sentinel lymph node biopsy (SLNB) was introduced 2 decades ago and thereafter validated for routine surgical management of breast cancer, including cases treated with neoadjuvant chemotherapy. As the number of lymph nodes for staging has decreased, pathologists have scrutinized SLN with a combination of standard hematoxylin and eosin, levels, immunohistochemistry (IHC), and molecular methods. An epidemic of small-volume metastases thereby arose, leading to modifications in the American Joint Committee on Cancer staging to accommodate findings such as isolated tumor cells (ITC) and micrometastases.

Are cytokeratin-positive cells in sentinel lymph nodes of patients with invasive breast carcinomas up to 5 mm usually insignificant?

Aims: It is known that sentinel lymph nodes (SLN) may be falsely positive due to displaced epithelial cells, particularly in cases with an underlying intraductal papilloma. Given the low metastatic rate in pT1a carcinomas, we aimed to investigate the effect of this phenomenon on staging.

Methods And Results: Using morphology and immunohistochemistry, we classified the epithelial cells in the SLN in 39 cases of pT1a carcinoma as positive for carcinoma in six, negative in 26 and undetermined in seven.

Breast pathology review: does it make a difference?

Background: Breast pathology is a challenging field, and previous work has shown discrepancies in diagnoses, even among experts. We set out to determine whether mandatory pathology review changes the diagnosis or surgical management of breast disease.

Methods: Cases were referred for pathology review after patients presented for surgical opinion to the Dubin Breast Center at Mount Sinai Medical Center over the course of 2 years.

Re-evaluating the role of sentinel lymph node biopsy in microinvasive breast carcinoma.

The role of sentinel lymph node biopsy in microinvasive breast carcinoma is unclear. We examined the incidence of lymph node metastasis in patients with microinvasive carcinoma who underwent surgery at our institution. Retrospective review of our pathology database was performed (1994-2012).

Characteristics of breast carcinoma cases with false-negative sentinel lymph nodes.

Background: In the past decade, sentinel lymph node biopsy (SLNB) has become standard for patients with early-stage clinically node-negative breast carcinoma (BC). Despite high overall surgical identification success rates with introduction of the dual-tracer techniques (dye and radiolabeled probe), false-negative rates remained unchanged in most recent meta-analyses.

Patients And Methods: We analyzed cases with false-negative SLN biopsy results over a 12-year period in a single institution to evaluate their clinicopathologic characteristics.