Leiomyosarcomas of the vein are an unusual type of tumor. The inferior vena cava is the commonest site of this lesion in the venous system and the ovarian vein is an extremely rare affected vessel. Only a few cases of LMS arising from the ovarian vein have been reported in the literature. The prognosis for patients is very poor due to the high metastatic potential by hematogenous spread.

This case has a differential diagnosis of a retroperitoneal tumor that could be either a malignant lymphoma, leiomyoma, or gastrointestinal stromal tumor.

However, the CT scan identified a retroperitoneal mass along with  the anatomical site of the left ovarian vein with typical radiological features of a gonadal vein leiomyosarcoma which were described in previous literature, hence suggestive of the diagnosis of ovarian vein LMS