Multiple retroperitoneal schwannomas mimicking adrenal tumors.

Schwannomas are benign tumors mostly arising from the head and neck. Retroperitoneal schwannomas are rare. Here we report the case of a 68-year-old woman with multiple retroperitoneal schwannomas. An abdominal computed tomography (CT) scan showed 1 non-enhancing mass with a low-density area, 4.6 cm in diameter, in the left adrenal region and another non-enhancing mass with a low-density area, 2.9 cm in diameter, in the para-aortic region. The patient had regularly undergone CT scans for malignant tumor screening in maintenance dialysis patients. Retrospectively, the 2 tumors had existed in the same regions in previous CT scans and had gradually increased in size. The tumors were completely resected. Pathological diagnosis of both tumors was schwannoma. When a CT scan shows a slowly growing retroperitoneal tumor with a low-density area, schwannoma should be considered. If the tumor increases in size, complete resection should be performed for pathological diagnosis.