Abstract
INTRODUCTION AND IMPORTANCE: Solitary fibrous tumor (SFT) is an uncommon mesenchymal tumor that can manifest in a variety of locations, including the retroperitoneum. The most effective standard diagnostic approach and treatment is yet to be determined due to unpredictable behavior of SFT, including retroperitoneal SFT. CASE PRESENTATION: A 43-year-old female with a retroperitoneal SFT presented with a palpable mass and symptomatology. Surgical exploration disclosed a tumor encompassing the left renal artery and vein, necessitating left nephrectomy and retroperitoneal mass removal. Initial histological examination suggested rhabdomyosarcoma, but subsequent immunohistochemistry confirmed the diagnosis of retroperitoneal SFT. No adjuvant therapy was administered, and there was no detectable mass on follow-up imaging. The patient remained symptom-free. CLINICAL DISCUSSION: Retroperitoneal SFTs are difficult to diagnose due to their non-specific morphology, thus immunohistochemistry plays a crucial role in confirming its diagnosis. Surgical excision with negative resection margins continues to be the standard treatment. Recurrence rates are low in comparison to other retroperitoneal sarcomas, hence routine chemotherapy or radiation therapy is not advised. CONCLUSION: This case demonstrates the significance of contemplating SFT as the differential diagnosis of retroperitoneal tumors and the role of immunohistochemistry in confirming the diagnosis. The optimal management strategies for retroperitoneal SFTs should be determined by additional research.