Uterine tumors resembling ovarian sex cord tumors: rare case report and literature review

Uterine tumors resembling ovarian sex-cord tumors (UTROSCT) are rare mesenchymal neoplasms with low malignant potential and polyphenotypic immunoprofiles. A 38-year-old nullipara presented with menorrhagia; trans-vaginal ultrasound revealed a 26-mm, richly vascular submucosal mass. Complete hysteroscopic excision was achieved without residual disease. Microscopy showed anastomosing cords, hollow tubules and bland spindled cells (0-1 mitosis/10 HPF). Immunohistochemistry demonstrated diffuse AE1/3, CD56, WT-1 and synaptophysin positivity, while inhibin-α, calretinin and ER/PR were negative; desmin highlighted entrapped myometrium. Ki-67 index was ~5%. Break-apart FISH and next-generation sequencing (141-gene solid-tumor panel) disclosed no pathogenic fusions involving ESR1, GREB1, NCOA2/3 or NR4A3, nor mutations in TP53, BRCA1/2 or mismatch-repair genes, consistent with the fusion-negative UTROSCT subset (~30-45% of cases). At 20 months the patient is disease-free with regular menses and intact fertility. We review diagnostic clues, differential diagnoses, molecular taxonomy and fertility-sparing strategies, underscoring the value of comprehensive genomic profiling for accurate classification and prognostication of this uncommon uterine tumor.