CT AND MRI FINDINGS IN A CASE OF PELVIC SCHWANNOMA

We compared the diagnostic utility of computed tomography (CT) and mag netic resonance imaging (MRI) in a patient with a pelvic schwannoma. T his 46-year-old woman was admitted for evaluation of a retroperitoneal pelvic mass and myoma uteri. The retroperitoneal pelvic mass had been detected by a CT scan at a routine health examination. A CT scan reve aled a well-circumscribed cystic tumor (4 x 3 cm) at the right interna l obturator muscle portion. The CT number of the inner part of the tum or was 21. Only the cyst wall was enhanced by injection of a contrast medium. MRI showed a 4 x 3 x 3-cm retroperitoneal cystic tumor that de monstrated low-intensity signals on T1-weighted images and high-intens ity signals on T2-weighted images. Small areas of low intensity inside the tumor were observed on T2-weighted images. Histological examinati on revealed a typical schwannoma of mixed Antoni type A and type B. Th ese findings indicate that both MRI and CT are useful for diagnosis of retroperitoneal schwannomas.