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[Retroperitoneal giant schwannoma: a case report and review of the literature].

Schwannomas are rare tumours that originate in the neural sheath and account for only a small percentage of all retroperitoneal tumours. They are usually solitary, circumscribed and encapsulated lesions eccentrically located on proximal nerves or spinal nerve roots. Presentation is typically varied and non-specific, ranging from abdominal pain, an abdominal mass or an incidental finding. The preoperative diagnosis is difficult and laboratory tests are usually unremarkable. We report the case of a 66-year-old female presenting with abdominal pain in her left flank and with an ultrasonographic diagnosis of a left kidney mass. She was diagnosed as suffering from a giant retroperitoneal schwannoma after surgical exploration and complete excision. The role of CT scan and CT-guided needle biopsy is emphasised, in that ultrasonography and fine needle aspiration alone do not provide sufficient information regarding aetiology and malignancy. Radical surgical excision is curative but recurrences may occur. Careful follow-up is needed.