Title: Peripjeral nerve mucoid degeneration/ inraneural pseudocyst/ intraneural ganglion/ intraneural ganglion cyst: solving the enigma

Biography:

Arjun Handa , is from  Army Hospital Research and Referral, New Delhi, India.

Abstract

Statement of the Problem: Inraneural ganglion cyst of peripheral nerves is a rarely reported entity. Lack of widespread knowledge and understanding of the condition may be the cause of possible under reporting of these cases and also possibly why it has remained an enigma since early nineteenth century. Methodology & Theoretical. Orientation:With an emerging new hypothesis and increasing awareness the number of cases reported in the last two decades have increased. Much of them have been diagnosed retrospectively. Clinically it presents usually in 4th to 5th decade with male preponderance with pain in typical peripheral nerve distribution with or without preceding history of minor trauma. The pain may be fluctuating with associated paraesthesia and weakness in muscles supplied by the nerve. The appearance of clinical signs after exertion is characteristic. Weakness may aggravate to paralysis which can be irreversible in long standing cases. Examination may reveal a palpable tender mass along the course of the nerve, usually in proximity to a joint. Electrodiagnostic studies are suggestive of entrapment neuropathy in its different stages from conduction block to neurological deficit. Radiological studies are invaluable in diagnosing the condition although the lesion and its characteristic features have to be actively looked for to arrive at a conclusive diagnosis. Pathology is characterised by the infiltration of the neural sheath by a mucoid substance which forms an intra-neural tumour, compressing the nerve fascicles towards the periphery. There is no epithelial lining around the cyst and the pathogenesis is controversial. Differential diagnosis includes other nerve tumours, nerve-entrapment syndrome or a compressive articular synovial cyst. Intra operatively, it appears as intra neural bluish cyst along the nerve of which yields translucent yellowish fluid on epineurotomy.

 Findings: Management is surgical decompression with excision of the intra-articular branch which is essential in reducing recurrence. Early intervention gives good recovery in about 10 months. No intrafascicular dissection or resection followed by bridge grafting is to be carried out. & Significance: The emerging hypothesis about its pathogenesis as a ganglion from adjacent joint and spreading along the articular branch of the nerve is gaining ground which has implication on its management. Here we present cases we encountered in a tertiary care centre over a period of two years with their management and follow up.