The Evolving Molecular Landscape of Uterine Mesenchymal Tumors: Diagnostic and Therapeutic Implications

Uterine mesenchymal tumors encompass a diverse and diagnostically challenging group of neoplasms, including smooth muscle tumors, endometrial stromal tumors (ESS), perivascular epithelioid cell tumors (PEComas), inflammatory myofibroblastic tumors (IMTs), uterine tumor resembling ovarian sex cord tumor (UTROSCT), along with many other relatively rare entities. Traditionally classified by histomorphology and immunophenotype, these tumors are now increasingly defined by recurrent genetic alterations that refine diagnosis and elucidate tumorigenesis. For example, leiomyosarcomas display complex genomic instability with frequent TP53, RB1, and ATRX mutations. Low grade-ESS are characterized by JAZF1::SUZ12 and other related fusions, whereas high-grade tumors harbor YWHAE::NUTM2 or ZC3H7B::BCOR fusions, and BCOR internal tandem duplication (ITD) alterations. PEComas frequently contain TSC1 or TSC2 mutations, leading to aberrant activation of the mTOR pathway. Beyond their diagnostic utility, these molecular signatures increasingly inform prognosis and highlight potential therapeutic targets, including CDK4/6 inhibition, PI3K/AKT/mTOR blockade, and immunotherapy. This review summarizes the evolving molecular landscape of uterine mesenchymal tumors, underscoring the value of integrating molecular testing into clinical practice to enhance diagnostic precision and enable personalized management of these rare yet clinically significant neoplasms.