Primary extraskeletal osteosarcoma of rectal mesentery: a rare case and literature review.

Background: Extraskeletal osteosarcoma (ESOS) is a rare kind of sarcoma with a low preoperative diagnosis and a poor prognosis. ESOS arising from abdominal mesentery is extremely rare. Increasing diagnostic methods and standardizing treatment protocols are crucial issues of ESOS.

Case presentation: We report the case of a 52-year-old female ESOS patient. She had a history of ovarian carcinoma (stage IIIC) surgery two years before, with five cycles of chemotherapy. A mass was found during postoperative examinations. A R0 surgical resection was performed. Post-operational pathological report plus intra-surgery findings supported a diagnosis of ESOS. She is still alive 10 months post-operationally, with routine blood and radiographical examinations.

Conclusion: Enhancing awareness of this extremely rare disease together with advancements in diagnostic methods will hopefully enable earlier recognition and initiation of treatment. Protocols for standardizing treatments require a larger multi-center collaboration and more data analysis.