Malignant Brenner Tumor of the Ovary: A Critical Reappraisal.

Malignant Brenner tumors (MBTs) are rare epithelial tumors of the ovary, most likely arising from benign and borderline Brenner tumors. MBTs may be misdiagnosed as other primary carcinomas or nonepithelial tumors of the ovary as well as metastatic carcinomas. Accurate diagnosis usually requires clinical-radiologic correlation, extensive sampling, and immunohistochemical studies.

Presence and extent of lymphovascular invasion in surgical stage I squamous cell carcinoma of the cervix: a comprehensive, international, multicentre, retrospective clinicopathological study.

The aim of this study was to determine whether the presence and extent of lymphovascular invasion (LVI) is prognostic in surgical stage I cervical squamous cell carcinoma (SCC). All available tumour slides and/or paraffin blocks from 426 patients with stage I cervical SCC treated surgically with curative intent were collected from 18 institutions and retrospectively analysed. Presence and extent of LVI (focal <5 spaces, extensive ≥5 spaces) were assessed on scanning magnification in large haematoxylin and eosin slide sets in 366 cases.

Validation Study of the Newly Proposed Refined Diagnostic Criteria for Malignant Phyllodes Tumor With 136 Borderline and Malignant Phyllodes Tumor Cases.

The World Health Organization (WHO) diagnostic criteria for malignant phyllodes tumor (MPT) may miss a significant number of MPTs with metastatic potential. New refined diagnostic criteria (Refined Criteria) for MPT were recently proposed. The aim of this study is to validate the Refined Criteria.

The Malignant Potential of Ovarian Steroid Cell Tumors Revisited: A Multi-institutional Clinicopathologic Analysis of 115 Cases.

Steroid cell tumors (SCTs) of the ovary are rare and understudied, and as such, uncertainties remain about their malignant potential, as well as clinicopathologic predictors of patient outcome. Based on a multi-institutional cohort of cases, we present findings from the largest study of SCT reported to date. Clinicopathologic data were documented on 115 cases of SCT that were assembled from 17 institutions.

Identification of Glandular (Acinar)/Tubule Formation in Invasive Carcinoma of the Breast: A Study to Determine Concordance Using the World Health Organization Definition.

Context.—: The Nottingham Grading System (NGS) developed by Elston and Ellis is used to grade invasive breast cancer (IBC). Glandular (acinar)/tubule formation is a component of NGS.

Subspecialized breast pathologists have suboptimal interobserver agreement in Ki-67 evaluation using 20% as the cutoff.

Purpose: Ki-67 expression levels in breast cancer have prognostic and predictive significance. Therefore, accurate Ki-67 evaluation is important for optimal patient care. Although an algorithm developed by the International Ki-67 in Breast Cancer Working Group (IKWG) improves interobserver variability, it is tedious and time-consuming.

Sarcomas With RAD51B Fusions Are Associated With a Heterogeneous Phenotype.

RAD51B-rearranged sarcomas are rare neoplasms that exhibit a heterogeneous morphology. To date, 6 cases have been reported, all involving the uterus, including 4 perivascular epithelioid cell tumors (PEComas) and 2 leiomyosarcomas (LMS). In this study, we describe the morphologic, immunohistochemical, and molecular features of 8 additional sarcomas with RAD51B rearrangement, including the first extrauterine example.

Teratoma-associated and so-called pure Wilms tumour of the ovary represent two separate tumour types with distinct molecular features.

Aims: Ovarian Wilms tumour (WT)/nephroblastoma is an extremely rare neoplasm that has been reported to occur in pure form or as a component of a teratomatous neoplasm. We hypothesized that teratoma-associated and pure ovarian WT may represent different tumour types with diverging molecular backgrounds. To test this hypothesis, we comprehensively characterized a series of five tumours originally diagnosed as ovarian WT.

Targeted RNA Sequencing Highlights a Diverse Genomic and Morphologic Landscape in Low-grade Endometrial Stromal Sarcoma, Including Novel Fusion Genes.

Low-grade endometrial stromal sarcoma (LGESS) represents a morphologically and genetically heterogenous mesenchymal neoplasm. Previous work has shown that approximately half of LGESS are characterized by JAZF1::SUZ12 gene fusions, while a smaller proportion involves rearrangement of other genes. However, a subset of cases has no known genetic abnormalities.

Intraoperative assessment of axillary sentinel lymph nodes by telepathology.

Purpose: Although axillary dissection is no longer indicated for many breast cancer patients with 1-2 positive axillary sentinel lymph nodes (ASLN), intraoperative ASLN assessment is still performed in many institutions for patients undergoing mastectomy or neoadjuvant therapy. With recent advancements in digital pathology, pathologists increasingly evaluate ASLN via remote telepathology. We aimed to compare the performance characteristics of remote telepathology and conventional on-site intraoperative ASLN assessment.

Mammary Spindle Cell Proliferations on Core Needle Biopsy: Is Excision Always Necessary?

Mammary spindle cell proliferations (SCPs) encompass a wide range of lesions and can be challenging to accurately diagnose on core needle biopsies (CNBs). Most SCPs are excised for definitive diagnosis. In the era of minimally invasive therapy, some SCP may be followed conservatively.

Inflammatory Lesions of the Breast.

Context.—: Inflammatory lesions of the breast are rare but not infrequently pose problems both clinically and morphologically, particularly on needle core biopsies. These lesions range from acute inflammatory conditions to chronic lymphoplasmacytic and lymphohistiocytic to granulomatous inflammatory diseases.

Practical Updates and Diagnostic Challenges in Endometrial Carcinoma.

Context.—: Clinical management of endometrial carcinoma largely depends on the morphologic parameters ascertained based on the pathologic evaluation of surgical resection specimens. However, there are numerous controversial and nonstandardized aspects of both the macroscopic and microscopic assessment of surgical specimens, including grossing, adequate sampling, diagnosis, staging, reporting, and ancillary testing.

Gestational trophoblastic disease: an update.

Gestational trophoblastic diseases (GTD) encompass a spectrum of rare pre-malignant and malignant entities originating from trophoblastic tissue. This updated review will highlight important radiological features, pathology and classification, and provide insight into the clinical management of these uncommon disorders. There is a wide geographic variation with the incidence of hydatidiform mole varying between 0.

Expanding the molecular spectrum of gene fusions in endometrial stromal sarcoma: Novel subunits of the chromatin remodeling complexes PRC2 and NuA4/TIP60 as alternative fusion partners.

Endometrial stromal sarcomas (ESS) are morphologically and molecularly heterogeneous. We report novel gene fusions (EPC1::EED, EPC1::EZH2, ING3::PHF1) identified by targeted RNA sequencing in five cases. The ING3::PHF1-fusion positive ESS presented in a 58-year-old female as extrauterine mesocolonic, ovarian masses, and displayed large, monomorphic ovoid-to-epithelioid cells arranged in solid sheets.

Uterine Sarcoma With FGFR1-TACC1 Gene Fusion: A Case Report and Review of the Literature.

With the growing availability of RNA sequencing technology in the pathology laboratory, new gene fusion-associated malignancies are increasingly being characterized. In this article, we describe the second ever reported case of a uterine sarcoma harboring a FGFR1-TACC1 gene fusion. The patient, a 53-yr-old perimenopausal woman, was found to have a 6 cm mass spanning the lower uterine segment and endocervix.

Recurrent uterine inflammatory myofibroblastic tumor previously managed as leiomyosarcoma has sustained response to alectinib.

Soft tissue sarcomas encompass a wide range of histologic subtypes with varied clinical implications. The incorporation of comprehensive genetic profiling into clinical practice is refining our ability to make these distinctions in diagnosis to better reflect prognosis and clinical behavior of a tumor. In this report, we describe a case of recurrent inflammatory myofibroblastic tumor (IMT) of the uterus, initially diagnosed and managed as leiomyosarcoma.

Are Columnar Cell Lesions the Earliest Non-Obligate Precursor in the Low-Grade Breast Neoplasia Pathway?

Columnar cell lesions (CCLs) of the breast comprise a spectrum of morphologic alterations of the terminal duct lobular unit involving variably dilated and enlarged acini lined by columnar epithelial cells. The World Health Organization currently classifies CCLs without atypia as columnar cell change (CCC) and columnar cell hyperplasia (CCH), whereas flat epithelial atypia (FEA) is a unifying term encompassing both CCC and CCH with cytologic atypia. CCLs have been increasingly recognized in stereotactic core needle biopsies (CNBs) performed for the assessment of calcifications.

Recurrent KAT6B/A::KANSL1 Fusions Characterize a Potentially Aggressive Uterine Sarcoma Morphologically Overlapping With Low-grade Endometrial Stromal Sarcoma.

With the widespread application of next-generation sequencing, the genetic landscape of uterine mesenchymal neoplasms has been evolving rapidly to include several recently identified fusion genes. Although chromosomal rearrangements involving the 10q22 and 17q21.31 loci have been reported in occasional uterine leiomyomas decades ago, the corresponding KAT6B::KANSL1 fusion has been only recently identified in 2 uterine tumors diagnosed as leiomyoma and leiomyosarcoma.