Endometrial Stromal Sarcomas With BCOR Internal Tandem Duplication and Variant BCOR/BCORL1 Rearrangements Resemble High-grade Endometrial Stromal Sarcomas With Recurrent CDK4 Pathway Alterations and MDM2 Amplifications.

The distinction between low-grade and high-grade endometrial stromal sarcomas (LGESS, HGESS) is increasingly defined by genetics. Recently, variant genomic alterations involving BCOR or BCORL1 have been reported in endometrial stromal sarcoma (ESS), although it remains unclear whether these justify a diagnosis of LGESS or HGESS. In this study, we describe clinicopathologic and molecular features of ESS with such alterations to help clarify their classification in the spectrum of ESS. We collected a cohort of 13 ESS harboring variant alteration involving BCOR (6 with internal tandem duplication, 1 with EP300::BCOR fusion, 1 with BCOR::LPP fusion) and BCORL1 ( 4 with JAZF1::BCORL1 fusion, 1 with EPC1::BCORL1 fusion). The median patient age at primary diagnosis was 51 years (range: 18 to 70 y). Median tumor size at primary diagnosis was 9.3 cm (range: 4.5 to 21 cm), and extrauterine disease spread (stage IIIB-C) was present in 27%. The tumors were composed of round to spindled cells with cellularity and cytologic atypia ranging from mild to marked and a median mitotic count of 18/10 HPFs (range: 2 to 85/10 HPFs). At least focally myopermeative growth was noted in 8/8 assessable cases. Of 12 patients with follow-up data (median: 25 mo), 4 patients died of disease and 3 were alive with recurrent disease. Unsupervised hierarchical clustering of DNA methylation data together with a large cohort of uterine mesenchymal tumors that included YWHAE::NUTM2 and Z C3H7B::BCOR HGESS and molecularly confirmed LGESS revealed a common methylation signature for all ESS with variant BCOR and BCORL1 alterations and HGESS with YWHAE::NUTM2 and ZC3H7B::BCOR gene fusion. Copy number analysis revealed amplifications of CDK4 and MDM2 , as well as homozygous deletions of CDKN2A/B and NF1 in a subset of tumors. Our results indicate that ESS with BCOR internal tandem duplication and variant BCOR and BCORL1 rearrangements clinically and molecularly resemble conventional HGESS.

BCOR Internal Tandem Duplication Associated Uterine Sarcoma: Expanding the Clinicopathologic Spectrum.

The diagnosis of high-grade endometrial stromal sarcoma has become more refined following molecular characterization of these tumors. Recently BCOR internal tandem duplications (ITD) have been identified in a small number of high-grade endometrial stromal sarcoma. Here we present an additional case of this rare entity in a young woman in her late teens. She presented with menorrhagia and underwent resection of 2 uterine lesions. The tumor was a spindle cell neoplasm composed of long fascicles with low to moderate cellularity, mild to moderate cytologic atypia, and up to 2 mitotic figures per 10 high power fields. Necrosis was not identified. Immunohistochemical stains showed the tumor to be positive for cyclin D1 in >50% of tumor cells, focally positive for CD10, and negative for SMA, desmin, h-caldesmon, and ALK1. BCOR ITD was confirmed by polymerase chain reaction with subsequent Sanger sequencing. Clues to the diagnosis of BCOR ITD uterine sarcoma include young patient age, uniform nuclear features, and diffuse positivity for cyclin D1. These features should prompt further molecular interrogation for definitive diagnosis, which is important for prognostication.

PLAG1-rearrangment in a uterine leiomyosarcoma with myxoid stroma and heterologous differentiation.

A variety of molecular alterations have been reported in uterine leiomyosarcomas, but most are considered nondiagnostic. There are, however, rare exceptions including PLAG1 rearrangement which has recently been identified in a subset of myxoid leiomyosarcomas. A 41-year-old woman presented with symptoms of a fibroid. She underwent a myomectomy which revealed a high-grade uterine sarcoma with areas of myxoid stroma and heterologous elements. The tumor expressed desmin, smooth muscle actin, H-caldesmon, and estrogen and progesterone receptors. RNA sequencing revealed a novel TRIM13-PLAG1 fusion gene which was subsequently independently confirmed by fluorescence in situ hybridization. On further evaluation the patient was found to have multiple pulmonary metastases and died due to disease progression shortly after diagnosis. This report describes a novel fusion partner of PLAG1 in a uterine leiomyosarcoma with myxoid leiomyosarcoma and heterologous elements, thereby broadening the spectrum of morphologic and genetic findings within this rare group of neoplasms.

Biomarkers of outcome to weekly paclitaxel in epithelial ovarian cancer.

OBJECTIVE: We sought to evaluate the role of intrinsic chromosomal aberrations in determining favorable outcome to weekly paclitaxel (WP) in patients with epithelial ovarian cancer (EOC). METHODS: We evaluated the common genomic aberrations of two patients with EOC and exceptional WP response in the GENIUS study (NCT03740503). We then searched for potential markers of unusual outcomes to WP in a validation cohort. We performed shallow whole genome sequencing (sWGS) in the tumor tissue of women with EOC considered as short-responders (SR; progression with ≤3 cycles) and long-responders (LR; response at ≥8 cycles) to WP monotherapy. RESULTS: We identified two women with exceptional response to WP, lasting over four years, who shared chromosome 8 gain as a common genomic aberration. In order to validate our findings, we reviewed 188 patients with EOC treated with WP and selected 61 women (39 SR, 22 LR) with unusual responses. By sWGS, there was no differential alterations in the copy number changes in chromosome 8, or in genes related to angiogenesis, tubulin superfamily, cell-cycle, apoptosis and paclitaxel metabolism or transportation pathways. Amongst the LR group, we identified six exceptionally long responders (ExLR), with responses lasting over a year. In an exploratory analysis, there was increased amplification of angiogenesis (VEGFB, MMP9), tubulin superfamily (TSC2) and apoptosis related genes (BCL2L1, BAD) in ExLR compared to SR. We identified one patient with a complete response to WP for over 7 years. Molecular profiling identified unique amplifications in interleukin related genes (CXCR1, CXCR2, IL1A, IL1B), not detected in other patients. CONCLUSION: Intrinsic tumor pathways may impact outcome with weekly paclitaxel monotherapy and further investigations are required.

A Case of Postpartum Anogenital Mammary-Like Gland Tumor with Focal Lactational Features: A Nomenclature Issue.

Mammary-like glands (MLG) are considered to be a normal constituent of the anogenital region and can give rise to tumors with variable morphology that may be difficult to classify. We present a case of an anogenital mammary-like gland tumor in a breastfeeding woman showing morphological variation with lactational change, an unusual finding. We discuss the differing terminology used to report these tumors and the variation in assignment of their origin to MLG or ectopic breast tissue.

Neoadjuvant therapy in gynaecological malignancies: What pathologists need to know.

In recent times, there has been a growing tendency to treat advanced gynaecological malignancies with neoadjuvant chemotherapy (NACT), with the goal of reducing tumour volume and enhancing operability resulting in optimal cytoreduction. This approach is used in particular for patients with advanced high-grade serous carcinoma of the ovary, fallopian tube or peritoneum. Pathology plays a crucial role in the management of these patients, both before and after NACT. Prior to initiation of NACT, a biopsy should be performed, usually of the omental cake, to confirm that a malignancy is present, to identify the site of origin of the tumour and to type and grade the tumour. Histopathologists must be aware of the resultant morphological effects of NACT when examining specimens following interval cytoreduction surgery. Tumour typing and grading, and even the identification of residual neoplasia, are particular challenges. Immunohistochemistry, when used judiciously, can be a useful adjunct in certain scenarios. A pathological assessment of the response to chemotherapy, and the pathological stage should be provided in the pathology report, as these may inform prognosis and subsequent management. We present a comprehensive overview of the relevant clinical and pathological aspects pertaining to NACT for gynaecological malignancies for the practicing surgical pathologist.

Differentiating between endocervical glandular neoplasia and high grade squamous intraepithelial lesions in endocervical crypts: cytological features in ThinPrep and SurePath cervical cytology samples.

A recent audit at our institution revealed a higher number of cases diagnosed as endocervical glandular neoplasia on ThinPrep (TP) cervical cytology samples (9 cases) as opposed to SurePath (SP) (1 case), which on histology showed only high-grade cervical intraepithelial neoplasia (CIN) with endocervical crypt involvement (CI). We attempted to ascertain the reasons for this finding by reviewing the available slides of these cases, as well as slides of cases diagnosed as glandular neoplasia on cytology and histology; cases diagnosed as high-grade squamous intraepithelial lesions (HSIL) on cytology which had CIN with CI on histology and cases with mixed glandular and squamous abnormalities diagnosed both cytologically and histologically. Single neoplastic glandular cells and short pseudostratified strips were more prevalent in SP than TP with the cell clusters in glandular neoplasia 3-4 cells thick, in contrast to the dense crowded centre of cell groups in HSIL with CI. The cells at the periphery of groups can be misleading. Cases with HSIL and glandular neoplasia have a combination of the features of each entity in isolation. The diagnosis of glandular neoplasia remains challenging and conversion from conventional to liquid based cervical cytology requires a period of learning and adaptation, which can be facilitated by local audit and review of the cytology slides in cases with a cytology-histology mismatch.