Primary gastric synovial sarcoma: A case report and literature review

•Primary synovial sarcoma (SS) of the stomach is a very rare disease.•To date, only 39 gastric SS cases have been reported in the literature.•Here is a report of a surgically resected primary gastric SS case and a review of the corresponding literature. Synovial sarcoma (SS) is a mesenchymal neoplasm that is characterized by its unique histological pattern and is most commonly found near the joints of the extremity. Stomach involvement is very rare. This work aimed to present the case of a patient with gastric SS. We also conducted a review of 39 gastric SS cases reported in the literature. Here we report a case of primary gastric synovial sarcoma in a 32-year-old male patient revealed by gastric reflux. Partial gastrectomy was performed showing a 35 mm lesion with a high spindle cell component. Immunohistochemistry revealed 18q11.2 translocation expression in most of the cells asserting a diagnosis of SS. No local or distant recurrence occurred at 8 months post-operative follow-up. The majority of SS occurs in the extremities and is most often associated with tendons in the large articulations of young adults. Gastric SS are very scarce and a molecular biology approach to detect the SYT-SSX fusion gene is required for conclusive diagnosis. We carried out a clinical review of the 40 cases of primary gastric SS, including our case. They all underwent an excisional surgery, most of them by partial gastectomy or wedge resection. Recurrences were rare and early when they occurred. Gastric SS is a very uncommon neoplasia although it is henceforth a described entity. Immunohistochemical detection of a pathognomonic translocation is needed to make the diagnosis of SS. Best therapeutic approach for these tumors remains surgical resection with no specific excisional technique recommended.