Primary Monophasic Omental Synovial Sarcoma in Nulliparous Female: A Case Report

Abstract

Synovial Sarcoma (SS) is an uncommon soft-tissue malignancy that primarily occurs near tendon sheaths and bone joints. Its primary intra-abdominal location is infrequent and characterised by non specific clinical signs. The mainstay of treatment remains wide local excision with negative margins. Hereby the authors report a rare case of monophasic omental SS in a 30-year-old nulliparous female who presented with chief complaints of an enlarging lump in the right abdominopelvic region over the past year and constipation for three months. The mass was non mobile and non tender. The rest of the physical and laboratory examinations were normal. She has a history of diagnostic laparoscopic excision (for the same complaint) of bilateral adnexal masses with right salpingectomy done three months ago in an outside set-up where histopathology diagnosed the mass as a low-grade fibromyxoid tumour. Presently, Contrast- enhanced Magnetic Resonance Imaging (CEMRI) revealed a large lobulated heterogeneous mass of 19.5×15.4×20 cm extending into mesorectal fat and encasing the sigmoid colon, rectosigmoid junction, uterus, and bilateral ovaries. The patient was taken for emergency surgery as she started displaying symptoms of acute obstruction. Debulking surgery (R2 resection) with ileostomy was performed. Histopathology and immunohistochemistry confirmed the diagnosis of monophasic SS. The patient was started on doxorubicin and has completed three cycles of chemotherapy. SS is an infrequent entity with high mortality rates. The main course of treatment is surgery with healthy resection margins. Long-term follow-up is required due to the high recurrence rate.