Introduction

Type 2 neurofibromatosis (NF2) was probably first described by Wishart in (1822). He described a man with multiple intracranial tumors including what Wishart described as bilateral seventh nerve neuromas, but which Worster-Drought (1937) later suggested were probably eighth nerve tumors (previously called acoustic neuromas but now more accurately labeled vestibular schwannoma). However, following reports of patients with type 1 neurofibromatosis (NF1) by von Recklinghausen (1882), various reports of NF2 cases around the turn of the last century were lumped together with von Recklinghausen's disease. Probably the most responsible for the prolonged co-classification of NF1 and NF2 was none other than Harvey Cushing (1917).

Although many reports emphasized the lack of skin tumors or café-au-lait patches in patients and families with bilateral vestibular schwannomas (Gardner & Frazier 1930; Worster-Drought et al., 1937; Young et al., 1971), the final separation of NF1 and NF2 and their delineation only came in 1987. In that year the gene for NF1 was localized to chromosome 17 (Seizinger et al., 1987) and NF2 to chromosome 22 (Rouleau et al., 1987) by genetic linkage analysis. As a result of this and the increasing clinical evidence to implicate two distinct disorders (Kanter et al., 1980), the National Institutes of Health Consensus statement published that year (NIH statement 1987) formally separated them. The still widely held belief that vestibular schwannomas occur as part of NF1 has now been refuted by large population-based studies of the more common type 1 disease (Huson et al., 1988; McGaughran et al., 1999).