Abstract
Dear Sir,
A 42 year-old right handed woman was seen because of progressive pain in the right wrist of 2 years duration, including pain at night that routinely interrupted her sleep. She also suffered from numbness in the distribution of the right median nerve and wasting of the thenar muscles. She had no known history of trauma. On examination, there was a 2 −2 cm, elliptical, firm, subcutaneous mass on the flexor aspect of the wrist. Sensory examination identified paraesthesiae in the distribution of the median nerve with a positive Phalen’s test and Tinel’s sign. MRI of the right wrist showed a heteregeneous mass which appeared well circumscribed. The patient underwent release of the carpal tunnel and incisional biopsy of the mass. The mass extending for approximately 2 cm within the median nerve just proximal to the take-off of the motor branch (Fig 1). There were no postoperative complications and there has been sustained regression of the symptoms of carpal tunnel syndrome over the 16 months since surgery. During this period, there has been no clinical or radiological evidence of increase in size of the tumour.
Perineuriomas present as focal, intraneural, peripheral nerve, or isolated, soft tissue lesions. Intraneural perineuriomas, generally, present as a slowly progressive, painless, focal motor neuropathy. They are characterised histologically by onion-bulb-shaped whorls (Imaginariojda et al., 1964). The aetiology of these lesions is controversial, with some authors asserting that this is a reactive process to trauma and others proposing that this is a true neoplasm (Emory et al., 1995). In the recent literature, the lesion continues to be referred to interchangeably as a perineurioma and as a localised hypertrophic mononeuropathy (Gruen et al., 1998).
According to Jazayeri et al. (2000), there is no consensus as to the correct management of these lesions. However, these authors advocated excision of the lesion and interpositional nerve grafting, although return of sensory nerve function was not seen in their case. In our patient, we confirmed the diagnosis by incision biopsy and adopted a policy of conservative management. At this point in time, there appears to be no evidence to support either of these two treatment options over the other from an oncological point of view.