OBJECTIVE: To evaluate the clinical characteristics of primary retroperitoneal schwannomas.MATERIALS AND METHODS: Medical records of patients with primary retroperitoneal schwannoma were retrospectively reviewed. Clinical manifestations, diagnoses, treatments and
outcomes of the patients were analyzed.RESULTS: From 1960 to 2000, there were 764 cases of schwannomas diagnosed histopathologically at Taipei Veterans General Hospital. Of these, 17 cases were primary retroperitoneal
schwannomas. Sixteen cases (94%) were benign schwannomas, and 1 (6%) was malignant. The mean age at diagnosis was 56.4 (range 21-80) years. The mean follow-up period was 51.3 (range 2-169) months. Nine patients (52.9%) were male, and 8 were female. The most common presentations
were distension and pain over the tumor site which were experienced in 8 patients (47%).Eight patients (47.1%) had negative physical findings, and 7 (41.2%) had a self-palpable mass.Imaging studies including sonography, computerized tomography (CT) scanning, and magnetic resonance imaging (MRI) provided high accuracy for detecting and accessing the tumor masses.
Seven (41.2%) tumors were located in the pelvis, 4 (23.5%) in the perirenal area, 4 (23.5%) in nerve roots and 2 (12.3%) in the adrenal gland. Sixteen patients (94.1%) only underwent surgery for tumor resection while the other patient with the malignant retroperitoneal schwannoma also received only local radiotherapy due to schwannomatosis. Two surgical complications (12.5%) of nerve injury were noted. The overall 5-year cumulative survival rate was 87.84%; only the patient
with the malignant retroperitoneal schwannoma died 1 month after diagnosis. Local tumor recurrence was noted in 2 patients (11.8%) by a follow-up CT scan and MRI at 20 and 24 months after surgery,respectively. Both patients received conservative treatment for the recurrent tumor.
CONCLUSIONS: The results of this retrospective study show that local distension and pain are the most common presenting symptoms. Surgical resection is the mainstay of treatment, and postoperative adjuvant therapy is not indicated if complete resection of the tumor can be achieved.Patients with benign primary retroperitoneal schwannomas have a good prognosis.