Update on Endometrial Stromal Tumours of the Uterus

Abstract

Endometrial stromal tumours (ESTs) are rare, intriguing uterine mesenchymal neoplasms with variegated histopathological, immunohistochemical and molecular characteristics. Morphologically, ESTs resemble endometrial stromal cells in the proliferative phase of the menstrual cycle. In 1966 Norris and Taylor classified ESTs into benign and malignant categories according to the mitotic count. In the most recent classification by the WHO (2020), ESTs have been divided into four categories: Endometrial Stromal Nodules (ESNs), Low-Grade Endometrial Stromal Sarcomas (LG-ESSs), High-Grade Endometrial Stromal Sarcomas (HG-ESSs) and Undifferentiated Uterine Sarcomas (UUSs). ESNs are clinically benign. LG-ESSs are tumours of low malignant potential, often with indolent clinical behaviour, with some cases presented with a late recurrence after hysterectomy. HG-ESSs are tumours of high malignant potential with more aggressive clinical outcome. UUSs show high-grade morphological features with very aggressive clinical behavior. With the advent of molecular techniques, the morphological classification of ESTs can be integrated with molecular findings in enhanced classification of these tumours. In the future, the morphological and immunohistochemical features correlated with molecular categorisation of ESTs, will become a robust means to plan therapeutic decisions, especially in recurrences and metastatic disease. In this review, we summarise the morphological, immunohistochemical and molecular features of ESTs with particular reference to the most recent molecular findings.

Pulmonary Metastasizing Low-Grade Endometrial Stromal Sarcoma: Case Report and Review of Diagnostic Pitfalls

“…Since HG-ESS may contain an LG-ESS area, the whole area should be carefully examined; additionally, the observation of necrosis and increased mitosis favors an HG-ESS diagnosis. Finally, both LG-ESS and HG-ESS are known to have characteristic genetic changes (for LG-ESS, fusions of JAZF1-SUZ12 , JAZF1-PHF1 ; for HG-ESS, fusions of YWHAE-NUTM2, ZC3H7B-BCOR ); hence, it would be helpful to conduct a molecular test, if possible [ 26 , 27 , 28 ].…”

NTRK gene fusions in solid tumors: agnostic relevance, prevalence and diagnostic strategies

“…Several investigations were carried out on uterine sarcoma which accounts for about 3% of malignant tumors of the uterus 30 . According to recent observations, the high-grade form, with uncertain origin from the endometrial stroma, is related to rearrangements of NTRK genes and in particular NTRK1 and NTRK3 genes 31 .…”

Endometriales Low-Grade-Stromasarkom als Zufallsbefund bei sonografischem Verdacht auf ein degenerativ verändertes Myom in der Schwangerschaft

“…Hierbei beträgt der Anteil von Leiomyosarkomen 25-30 % [18]. Endometriumstromatumoren sind seltene mesenchymale Neoplasien der Gebärmutter mit einer Vielzahl histopathologischer, immunhistochemischer und molekularer Charakteristika [19]. Endometriale Stromasarkome (ESS) gehören nach der neuesten Tumorklassifikation der Weltgesundheitsorganisation (WHO) zur allgemeinen Kategorie der stromalen und endometriumähnlichen Tumoren (EST).…”