Laparoscopic management of obturator nerve schwannomas: experiences with 6 cases and review of the literature.

OBJECTIVES: To present our experiences in management of obturator nerve schwannomas by laparoscopy. PATIENTS AND METHODS: Six patients who were diagnosed preoperatively with pelvic tumors and histologically with obturator nerve schwannomas were treated by laparoscopy in our hospital between 1998 and 2009. Clinical data were obtained by a retrospective review of all the patients' medical records, radiologic reports, pathologic reports, and operation videos. RESULTS: A total of 6 tumors were found in 6 patients, none of which was correctly, preoperatively diagnosed as a schwannoma. In 5 of them, obturator nerve roots were identified to be associated with the tumors during the operation. All of the tumors were resected successfully by laparoscopy, including 2 resected by enucleation. Postoperatively, 2 patients developed a permanent neurological deficit, 2 patients developed transient nerve neuropathy but complete resolution within 8 weeks, and the other 2 developed no neurological deficit. Pathologic examination showed that all the tumors were benign schwannoma. At a mean follow-up of 24 months (range, 12 to 48 mo) postresection, all the patients remained free from recurrence. CONCLUSIONS: Pelvic schwannomas are rare and difficult to diagnose preoperatively. The intraoperative observation of the nerve running through the tumor may aid the diagnosis. Although obturator nerve injury does not seem to be associated with severe impairments, efforts should be made to preserve the integrity of the nerve. Laparoscopic surgery is a safe and feasible method for approaching benign schwannoma in the obturator fossa.

Value of frozen section analysis of enlarged lymph nodes during radical nephrectomy for renal cell carcinoma.

OBJECTIVES: To avoid unnecessary lymphadenectomy for renal cell cancer (RCC) in patients with retroperitoneal enlarged lymph nodes (ELNs). METHODS: Frozen section examination (FSE) of ELNs was used to evaluate the lymphatic status. In the present study, 114 patients with RCC underwent FSE of ELNs and concurrent regional lymphadenectomy. The results of FSE were compared with the final histopathologic results of lymphadenectomy. Some clinical tumor characteristics were also considered to improve the evaluation effect of the FSE. Multiple regression analysis was applied to define the independent risk factors for lymphatic metastasis. RESULTS: The final histopathologic results indicated that 36 patients (31.6%) had nodal metastases. In these 36 patients, the FSE of ELNs revealed positive findings in 32 patients and negative findings in 4 patients. The sensitivity, specificity, concordance, and false-negative rate of FSE was 88.9%, 100%, 96.5%, and 11.1%, respectively. Multivariate analysis revealed that distant metastasis and high T stage (T3-T4) were independent risk factors for lymphatic metastasis. When FSE indicated negative results, no nodal metastases were found (64 patients) without these 2 risk factors. CONCLUSIONS: ELNs in patients with RCC do not necessarily indicate metastatic disease, and more than one half of ELNs were benign. FSE of ELNs can be used to evaluate the lymphatic status. Using the findings from FSE and the clinical characteristics of the primary tumor, we can avoid unnecessary lymphadenectomy in patients with retroperitoneal ELNs.