Uterine tumor resembling an ovarian sex cord tumor associated with metastasis.

Uterine tumors resembling ovarian sex-cord tumors (UTROSCT) are very rare, usually benign uterine tumors, and are probably derived from uterine mesenchymal stem cells. In this case report, a unique case of a malignant UTROSCT is described. Four years after a diagnosis of UTROSCT of the uterine corpus, the patient developed obstructive ileus due to a large infiltrating tumor within the small bowel with the same morphology and expression pattern as the previously diagnosed UTROSCT. In addition, 2 benign gastrointestinal stromal tumors were detected in the same patient. This case indicates that although the majority of UTROSCT are benign tumors, some of them might undergo malignant transformation and have a metastatic potency.