Anti-Ma2 antibody related paraneoplastic limbic/brain stem encephalitis associated with breast cancer expressing Ma1, Ma2, and Ma3 mRNAs.(Short Report)

Paraneoplastic neurological syndromes are neurological degenerative disorders that occur in patients with neoplasms outside the nervous system, associated with anti-neuronal cell antibodies that provide antitumour immunity. Fifty per cent of the primary tumours associated with paraneoplastic limbic encephalitis are small cell lung carcinomas, and in about half of these there are antibodies against the Hu family of neuronal RNA binding proteins. (1-3) Onconeuronal proteins Mal, Ma2, and Ma3 have been identified as antigens for paraneoplastic encephalitis. (4-6) A review of 29 patients with anti-Ma (Ma1, Ma2, and Ma3) antibodies showed that anti-Ma2 antibody was present in all the cases, and 18 patients carried anti-Ma2 antibody alone. (6-8) In those 18 patients, a testicular tumour was present in 14 cases; other associated tumours included breast cancer, lung cancer, and follicular lymphoma.

Here we report the clinical and immunopathological findings in a female patient who presented with paraneoplastic limbic/brain stem encephalitis associated with atypical medullary breast carcinoma. The patient carried the antibody against Ma2 antigen, but not Ma1 or Ma3 antigen, and the cancer tissue expressed Ma1, Ma2, and Ma3 mRNAs.

CASE REPORT

A 69 year old woman was referred to our hospital for progressive amnesia and hypersomnia lasting for five months. She had also had diplopia and visual hallucinations for three months. She had had a total hysterectomy for uterine fibroids when she was 50. On admission in January 2002, her axillary temperature was 38.0[degrees]C and she had moderate depression, agitation, visual hallucination, amnesia, and hypersomnia. She had lost orientation in place and time, and her short term memory was severely impaired. Epileptic seizures were not documented. The pupils were equal in size and the light reflexes were spared. Her left eye was exophoric at rest, and its adduction was moderately impaired. She had supranuclear gaze palsy and her vertical gaze was completely impaired bilaterally. There were no pyramidal tract signs, cerebellar ataxia, or bulbar dysfunction. Muscle strength and sensation were normal.

Routine laboratory tests showed no abnormalities. These included tumour markers of carcinoembryonic antigen (CEA), neurone specific enolase (NSE), and squamous cell carinoma related antigen …