Giant posterior pararenal schwannoma: A case report and review of literature.

Schwannomas, arising from Schwann cells of peripheral nerve sheaths, are primarily benign tumors. They are rarely found in the retroperitoneal space. To date, ~30 cases on giant retroperitoneal schwannomas have been reported. Those with a location of pararenal space are even rarer. Clinically, they are often misdiagnosed as malignancies. In the present study, a case of a 35-year-old woman with a giant schwannoma measuring 13 × 8.5 × 6.5 cm in the posterior pararenal space of left retroperitoneum was presented, which was thought to be a malignant tumor from the result of computed tomography scan. Later postoperative pathology and immunohistochemistry were consistent with benign schwannoma. To the best of our knowledge, this was the largest posterior pararenal schwannoma reported in literature. It is significant to report this case, and summarize the characteristics, diagnosis, treatment and prognosis of the similar cases. Furthermore, a brief review of the previously published cases in literature is provided.