gms | German Medical Science

Objective: Perineuriomas (PN) are rare benign peripheral nerve sheath tumours with perineurial cell origin. Therapy regime is controversial and only sparse reports of single cases or small case series have been published. Aim of this report is to present our minimal surgical treatment regime and long-term neurological outcome in a series of 3 PN cases and compare it to the literature.

Methods: Retrospective analysis of 35 patients with a slow growing benign nerve sheath tumour treated over the last 3 years in our centre revealed a PN in three cases. Under microscopic assistance, the nerve was prepared over the affected distance followed by delicate opening of the epineurium over the complete distance and an interfascicular neurolysis. Intraoperative stimulation of each fascicle was performed and a biopsy was taken from a damaged fascicle with no motorfunction proving the diagnosis of an intraneural PN.

Results: Case One: A 56-year-old male patient with typical clinical and electroneurographical findings of carpal-tunnel-syndrome caused by a PN of the right median nerve presented to our neurosurgical department. The patient underwent 4 surgeries over a period of 30 years without long term benefit because of suspected carpal-tunnel-syndrome. Ultrasound and MRI of the right hand depicted nerve enlargement with hyperechoic perineurial tissue and still identifiable fascicular structure. Interfascicular neurolysis finally led to long term relief of the symptoms. Case Two: A 16-year-old left-handed male patient presented with a PN of the left ulnar nerve. Symptoms lasted over two years, showing a progressive atrophy of the intrinsic muscles of the left hand. Electrophysiological testing revealed an impairment of the left ulnar nerve, MRI showed tumorous nerve swelling. After interfascicular neurolysis the patient is able to play the guitar again. Case Three: A 17-year-old female patient complained about progressive impairment of foot elevation over a period of 3 years. Electrophysiological testing showed impairment of the left peroneal nerve and MRI of the left leg revealed a PN. Symptoms have slightly improved after interfascicular neurolysis.

Conclusion: Perineuriomas are rare benign tumours with a slow progression. Decompression and interfascicular neurolysis of the affected nerve showed subsidized improvement of the neurological deficits with good long term results and should be considered as an alternative to extended surgical treatment.