Solitary fibrous tumor in the preperitoneal space mimicking an intra-abdominal tumor

Solitary fibrous tumors (SFTs) are uncommon fibroblastic mesenchymal neoplasms that rarely metastasize. They were primarily considered intrathoracic tumors; however, recent studies have reported SFTs in extrathoracic locations. This report describes a rare case of an SFT in the preperitoneal space that mimicked an intra-abdominal tumor radiographically. A 67-year-old woman was diagnosed with an extrahepatic tumor through ultrasonography. Computed tomography revealed a nodule near the liver's left lobe at the upper abdominal midline. Laparoscopic tumor resection was performed to minimize undersampling and tumor seeding. Laparoscopy revealed a well-circumscribed tumor located in the preperitoneal space. The tumor was resected en bloc with a macroscopically negative margin. Histopathological examinations confirmed an SFT using immunohistochemistry. Adjuvant treatment was not administered. No residual lesions were reported at the 6-month and 1-year follow-ups. Although SFT rarely metastasizes, early diagnosis and treatment of SFTs should be emphasized to ensure optimal patient outcomes.