Supracubital perineurioma misdiagnosed as carpal tunnel syndrome: case report

BACKGROUND Perineuriomas have been defined as tumorous lesions of the peripheral nerves which derive from perineurial cell proliferation and may be associated with abnormalities on chromosome 22. CASE PRESENTATION Three years after a painful cubital vein procaine injection, a 33 year-old man developed a median nerve lesion, initially diagnosed as carpal tunnel syndrome. Symptoms progressed despite appropriate surgery. Clinical and electrophysiological re-evaluation revealed a fusiform mass at the distal upper arm, confirmed by MRI. Immunohistochemical studies classified the tumor as a mixed perineurioma and neuroma. CONCLUSIONS Perineurioma mixed with neuroma may potentially caused by the previous trauma or cytotoxic effects of procaine.