[Case report of angiomyolipoma of the posterior upper mediastinum].

A case of posterior upper mediastinal angiomyolipoma is reported. The patient was an asymptomatic 63-year-old female, in whom an abnormal shadow was detected on chest x-ray at medical examination. On computed tomogram, the mass was located in the right paravertebral upper mediastinum, and its density had a CT-number of 12. It had high MRI intensity. Since there remained a possibility of malignancy, thoracotomy was carried out. The resected tumor was soft in consistency and the size was 20 x 23 x 37 mm. Histological examination showed that the mass was composed of fatty tissue, smooth muscle, and vascular tissue. Therefore, the tumor was diagnosed as angiomyolipoma. Although angiomyolipomas are often found in the kidney, those in the mediastinum are very rare and there have been only 2 cases reported in the literature. We consider that angiomyolipoma is rare, but important in the differential diagnosis of mediastinal tumors.