title: Endometrial stromal tumors: the new WHO classification.
abstract: Endometrial stromal tumors are rare uterine mesenchymal neoplasms that have intrigued pathologists for years, not only because they commonly pose diagnostic dilemmas, but also because the classification and pathogenesis of these tumors has been widely debated. The current World Health Organization recognizes 4 categories of endometrial stromal tumor: endometrial stromal nodule (ESN), low-grade endometrial stromal sarcoma (LG-ESS), high-grade endometrial stromal sarcoma (HG-ESS), and undifferentiated uterine sarcoma (UUS). uterine sarcoma. These categories are defined by the presence of distinct translocations as well as tumor morphology and prognosis. Specifically, the JAZF1-SUZ12 (formerly JAZF1-JJAZ1) fusion identifies a large proportion of ESN and LG-ESSs, whereas the YWHAE-FAM22 translocation identifies HG-ESSs. The latter tumors appear to have a prognosis intermediate between LG-ESS and UUS, which exhibits no specific translocation pattern. This review (1) presents the clinicopathologic features of endometrial stromal tumors; (2) discusses their immunophenotype; and (3) highlights the recent advances in molecular genetics which explain their pathogenesis and lend support for a new classification system.
authors.affiliation: *Department of Pathology, Surrey Memorial Hospital, Surrey, BC, Canada †Department of Pathology, Stanford University, Stanford, CA.
authors.forename: Christopher M J
authors.initials: CM
authors.lastname: Conklin
authors.forename: Teri A
authors.initials: TA
authors.lastname: Longacre
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D001706:Biopsy; D002454:Cell Differentiation; D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins; D003937:Diagnosis, Differential; D016889:Endometrial Neoplasms / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000473:pathology; D036821:Endometrial Stromal Tumors / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000473:pathology; D005260:Female; D050939:Gene Fusion; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D060787:Neoplasm Grading; D009363:Neoplasm Proteins / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D010641:Phenotype; D063151:Polycomb Repressive Complex 2 / Q000235:genetics; D011237:Predictive Value of Tests; D018203:Sarcoma, Endometrial Stromal / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000473:pathology; D009626:Terminology as Topic; D014157:Transcription Factors; D014178:Translocation, Genetic
chemical_list: D014408:Biomarkers, Tumor; D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins; C430460:JAZF1 protein, human; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; C430461:SUZ12 protein, human; D014157:Transcription Factors; C576541:YWHAE-FAM22 fusion protein, human; D063151:Polycomb Repressive Complex 2