Endometrial/Endometrioid Stromal Tumors With Extensive Whorling and CTNNB1 Translocation : A Report of 3 Cases.

TitleEndometrial/Endometrioid Stromal Tumors With Extensive Whorling and CTNNB1 Translocation : A Report of 3 Cases.
Publication TypeJournal Article
Year of Publication2023
AuthorsBoyraz B, Paula ADa Cruz, Deveraux KA, Tran I, da Silva EM, Young RH, Snuderl M, Weigelt B, Oliva E
JournalAm J Surg Pathol
Date Published2023 Nov 01
Keywordsbeta Catenin, Biomarkers, Tumor, Endometrial Neoplasms, Endometrial Stromal Tumors, Female, Humans, In Situ Hybridization, Fluorescence, Mitosis, Sarcoma, Endometrial Stromal

Endometrial/endometrioid stromal tumors are rare and morphologically heterogenous, and their diagnosis may be challenging. We identified 3 endometrial/endometrioid stromal tumors with identical and previously undescribed histologic features and herein report their morphologic, immunohistochemical, and molecular profiles. Patients were 53, 62, and 79 years. Tumors were well-circumscribed, tan-yellow solid masses measuring 10.0, 11.0, and 18.7 cm, and were intramyometrial (n=2) or in the broad ligament (n=1). All showed small, tight whorls of epithelioid to slightly spindled tumor cells with minimal cytoplasm and negligible mitoses, multifocally associated with hyalinization and myxoid change set in a loose fibroblastic background with small, delicate vessels. This morphology was seen throughout in 1 tumor and in ∼20% and 70% of the 2 others with the remaining areas showing sex cord-like differentiation. Tumor cells expressed CD10 (3/3, 1 focal), calretinin (3/3 diffuse), WT1 (3/3 diffuse), estrogen receptor (1/1, diffuse). RNA-sequencing was successful in 1 tumor and revealed a GREB1-CTNNB1 in-frame fusion. All 3 tumors harbored a CTNNB1 translocation by fluorescence in situ hybridization correlating with nuclear β-catenin expression. Whole-genome DNA methylation analysis classified all 3 tumors within the low-grade endometrial stromal sarcoma reference class with flat copy number profiles. One patient (79-y-old) died of unrelated causes 2 months after surgery and the other 2 were alive without disease after 13 and 75 months. We have described a rare subset of endometrial/endometrioid stromal tumors with extensive whorling and a CTNNB1 translocation, expanding the morphologic and molecular spectrum of these neoplasms.

Alternate JournalAm J Surg Pathol
PubMed ID37584555
Related Faculty: 
Baris Boyraz, M.D., Ph.D.

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