Vivian Ma,Lawrence Turner,Robert van Wiltenburg,Conrad D Oja,Ananta Gurung,Shawn MacKenzie, Intra-Abdominal Malignant Solitary Fibrous Tumor with Peritoneal Dissemination: A Case Report International Journal of Surgical Case Reports 2021 2674-4171 http://dx.doi.org/10.31487/j.IJSCR.2021.01.01 https://www.sciencerepository.org/intra-abdominal-malignant-solitary-fibrous-tumor-with-peritoneal_IJSCR-2021-1-101 Abstract: Solitary fibrous tumor (SFT) is a rare mesenchymal tumor primarily found in the pleura, with occasional presentations in extra-pleural locations. SFTs are typically diagnosed based on compressive symptoms due to their large size. Most SFTs are benign with a low recurrence rate, with an overall good prognosis with an overall 5-year survival of over 90%. Approximately 12-22% of SFTs are malignant and are associated with a higher recurrence rate of up to 78%. Given the low incidence and sparse case series literature, no adjuvant therapies have demonstrated a survival benefit. We present the first case of abdominal malignant SFTs with peritoneal dissemination, describing the presentation, histopathology, treatment planning and surveillance.Keywords: Solitary fibrous tumor, peritoneal dissemination, intra-abdominal, retroperitoneal sarcoma, malignant solitary fibrous tumor