Intra-abdominal low-grade fibromyxoid sarcoma of the transverse mesocolon mimicking lymphoma.

Low-grade fibromyxoid sarcoma (LGFMS), first described by Evans in 1987, is a rare soft tissue tumor. LGFMS commonly involves the deep soft tissues of the lower extremities, inguinal area, shoulder, axilla, neck and buttock. Intra-abdominal LGFMS has been reported in ten cases in six English studies (small bowel, four cases; mesentery, two; falciform ligament, one; omentum, one; colon, one; diffuse, one), and radiologic imaging studies were done in four of the ten cases. In the present case, radiologic findings of LGFMS showed a well-demarcated multilobular hypoechoic mass on ultrasonography, a multilobular homogeneously enhancing solid mass in the transverse mesocolon on computed tomography and a mildly inhomogeneously enhancing solid mass with two different components on magnetic resonance imaging. We report the first case of LGFMS arising from the transverse mesocolon mimicking lymphoma in a young female patient.