Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 7 3 2022 11 01 101 104 Elham Nazar Department of Pathology, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran. Zohre Shabanzade Department of Pathology, Fajr Hospital, Marivan, Iran. Amir Ahmadi Department of Pathology, Fajr Hospital, Marivan, Iran. 2021 02 22 2021 05 10 Synovial sarcoma is a malignant mesenchymal neoplasm which com- monly arises in the extremities of adults, in close association with joint capsules. Only a few cases of synovial sarcoma occurring in the abdominal wall have been reported. We report an extremely rare case of monophasic synovial sarcoma of abdominal wall in a 58-year-old woman who had presented with painless left ante- rior abdominal wall mass. The patient underwent excisional surgery. Histological and immunohistochemistry examinations revealed monophasic synovial sarcoma. Base on the diagnosis, the patient received chemoradiation.Primary synovial sarcoma is rarely found in the anterior abdominal wall. But, it should be included in the differential diagnosis. https://crcp.tums.ac.ir/index.php/crcp/article/view/486