Uterine Endometrial Stromal Sarcoma on MRI and 18F-FDG PET/CT: A Case Report with Literature Review

Endometrial stromal sarcomas (ESS) are a rare group of malignant mesenchymal tumors arising from the connective tissue of the endometrium, which resemble cells in their proliferative stage. These tumors represent 6-20% of uterine sarcomas and less than 1% of primary uterine malignancies; being low-grade, the most frequently diagnosed. Diagnosis is based on surgical pathology, but imaging plays a very important role in staging, considering that approximately 30-50% of patients have extra uterine spread at the time of diagnosis, and this determines treatment. MRI can determine with high accuracy the extension and invasion of the lesion, but 18F-FDG PET/CT is more accurate for the detection of abnormal lymph nodes and distant metastases, thus combining these two modalities is the best approach.