Laparoscopic resection of retroperitoneal intra-psoas muscle schwannoma: A case report and extensive literature review

INTRODUCTION: Soft tissue tumors of Schwann cells in either the peripheral or cranial nerves are known as schwannomas or also as neurilemmomas. Limited data exists regarding psoas muscle schwannoma in the literature. Therefore, we have done an extensive literature review and found a total number of 46 cases of intra-psoas schwannoma including our case, which are summarized in this article along with reporting our new case. PRESENTATION OF CASE: We report a very rare case of primary left intra-psoas muscle schwannoma in a 39-year-old Saudi gentleman, smoker with an unremarkable medical and surgical history. The patient presented to the emergency department with exacerbated chronic lower abdominal pain since almost 2 years. After conforming the diagnosis, the patient was admitted electively and underwent uneventful laparoscopic hand-assisted resection. DISCUSSION: Schwannomas are neurogenic tumors which known to be solitary, benign, well circumscribed, encapsulated, and slow-growing tumors. Multiple imaging modalities are used to detect such a tumor. Although there is no consensus on the best surgical approach, endoscopic mini-laparotomy, laparoscopy (anterior [as in our case] or lateral), and robotic resection were reported with good outcomes. CONCLUSION: Retroperitoneal schwannoma and intra-psoas muscle variant are a rare entity, with slow growing rate and risk of malignant transformation. Therefore, high index of suspicion, good follow-up, and large-cohort studies are encouraged. (C) 2020 The Author(s). Published by Elsevier Ltd on behalf of IJS Publishing Group Ltd.