Introduction/Background Endometrial stromal sarcoma (ESS) is a rare and difficult to diagnose endometrial proliferation. It constitutes only about 0.2% of all uterine malignancies and is usually associated with a poor prognosis. SSE is usually misdiagnosed as a leiomyoma sometimes associated with a polyp. Both have nonspecific symptoms, which makes the diagnosis even more complex. Given the rarity of this neoplastic entity, the optimal management is quite dynamic and debatable

Methodology our study is a case report

Results We report here a rare case of a 35-year-old patient who presented for pregnancy with a presumptive diagnosis of leiomyoma, principle diagnostic hysteroscopy for cavitary assessment in the context of infertility revealed a fundial imprint of a FIGO 2–5 myoma associated with an endocavitary process similar to a necrobitic myoma which was resected two weeks later over a larger area of implantation compared to the time of diagnosis. Pathological analysis revealed a low-grade endometrial stromal sarcoma of 5.5 cm long axis, infiltrating >50% of the myometrium. As a result, the treatment plan was changed from conservative myomectomy to total interovarian hysterectomy.

Conclusion The aim of this case report is to highlight this uncommon tumour in young patients and to raise awareness of the need to consider this diagnosis, particularly when presenting with a rapidly enlarging uterine leiomyoma.