Pelvic solitary fibrous tumors: clinical manifestations, surgical management and long-term outcomes.

Background: Pelvic solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm with marked clinical and radiological heterogeneity, posing significant diagnostic challenges. Standardized management strategies remain lacking for special clinical scenarios, including paraneoplastic syndromes, synchronous primary malignancies, and pregnancy-associated incidental diagnosis. Methods: This single-center retrospective case series included 3 consecutive patients with histologically confirmed pelvic SFT who underwent surgical resection at Peking University Third Hospital between October 2018 and September 2025. Clinical, radiological, surgical, pathological, and long-term follow-up data were systematically collected, and a narrative literature review was conducted to refine clinical management. Results: The three patients presented with distinct rare phenotypes: a 17.5 cm giant tumor complicated by Doege-Potter syndrome, synchronous low-grade bladder urothelial carcinoma, and an asymptomatic tumor incidentally detected during twin pregnancy. All achieved R0 radical resection via individualized open, robot-assisted, or laparoscopic approaches, with no Clavien-Dindo grade ≥II perioperative complications. All tumors showed characteristic nuclear STAT6 positivity and CD34 expression, with uncommon MDM2/CDK4 and SMA/desmin co-expression. At median 36-month follow-up (3-84 months), no recurrence or metastasis was observed. Conclusions: Complete R0 resection is the cornerstone of pelvic SFT treatment. Individualized surgery is safe even for complex cases. STAT6 positivity is the diagnostic gold standard. High-risk patients may benefit from adjuvant radiotherapy, and lifelong follow-up is mandatory for late recurrence.