Neurofibromatose versus Schwannomatose*

Neurofibromatosis Type 1 and 2 (NF1 und NF2) are different forms of neurofibromatosis, well defined both clinically and genetically. In absence of typical clinical features of NF1 (café-au-lait-spots, cutaneous neurofibromas, Lisch-nodules) or NF2 (vestibular schwanoma) clinical classification is often not possible. Neurofibromas are more common in NF1 and schwannomas are typical for NF2, but pathological histology does not provide sufficient evidence for diagnosis. We describe 14 patients who presented with the clinical picture of multiple spinal tumours. Detailed family history, exact clinical examination including an ophthalmological examination led to the diagnosis of NF2 in four cases. Mutation analysis confirmed the diagnosis of NF2 in one case by identification of a 163 base pair deletion in the NF2 transcript. To investigate the expression of schwannomin and neurofibromin we stained tumour paraffin sections of six patients with antibodies against peptides of the NF1 and the NF2 protein. Based on preserved immunoreactivities we were able to exclude diagnosis of NF1 in three and NF2 in two cases. In four patients the clinical symptoms could confirm the diagnosis of schwannomatosis. Combining the results of clinical, neurogenetical and immunohistochemical examinations we could diagnose NF1 or NF2 in ten patients in total. Immunoreactivity led to the suggestion of NF2 in two patients; the other two patients whose tumours were not stained so far, could as yet not be classified for NF.