Giant lumbosacral plexiform neurofibroma without associated neurocutaneous syndrome: An unusual presentation

Abstract

Benign retroperitoneal and presacral neural sheath tumors of lumbosacral plexus in patients without Von-Recklinghausen's disease are quite rare with only few sporadic case reports. We report a case of giant unilateral plexiform neurofibroma of lumbosacral plexus extending into the thigh up to the level of knee joint in a patient without neurofibromatosis-1. Large unilateral retroperitoneal neurofibromas are rare while extension of the same up to the level of knee joint has not been reported yet. The purpose of the report is to highlight the characteristic imaging features in an unusual case of retroperitoneal neurofibroma extending up to the knee joint and thus avoiding unnecessary biopsy. Further imaging helps in defining presurgical extent of lesion, which in our case is essential as the lesion is seen extending along the entire course of the involved femoral nerve.