Intraneural Perineuriomas; a Rare Entity. Clinical, Surgical and Neuropathological Details in the Management of these Lesions

Abstract

Perineuriomas are rare benign peripheral nerve sheath tumors, which have only been included in the WHO classification system since 2000. They are divided into intraneural perineuriomas and soft tissue tumors. Intraneural perineuriomas were previously known as localized hypertrophic neuropathies. Because of their rarity there are only case reports in the literature. Between 1992 and 2006 surgery was performed on four patients suffering from intraneural perineuriomas in our hospital. All patients were males, aged five, ten, twenty and twenty-nine years old. One of the tumors occurred in the ulnar nerve, one in the common peroneal part of the sciatic nerve and two of them in the radial nerve. In a retrospective study the clinical, electrophysiological and imaging data of the patients was analyzed. Two of these patients had previously been treated with decompression and neurolysis of the nerve for the suspicion of a nerve compression syndrome. Revisions were necessary following progressive neurological deterioration postoperatively. Explorations of the nerves showed nerve tumors. The tumors were resected and nerve grafting was performed. These tumors tend to affect the nerves of the upper extremities in children or young adults. The predominant symptom is a slow-progressive paralysis. Two of the four patients showed a partial improvement of their motor and sensorial nerve deficits in the long-term follow-up following complete tumor resection and interpositional autologous nerve grafts. No relapse could be observed. In cases of slow-progressive neurological deficits of a peripheral nerve in young patients the differential diagnosis should include the intraneural perineuriomas.