There are three major clinically and genetically distinct forms of neurofibromatosis: neurofibromatosis types 1 and 2 (NF1 and NF2) and schwannomatosis. NF1, also known as von Recklinghausen disease, is the most common type. The hallmarks of NF1 are the multiple café-au-lait macules and neurofibromas. The condition is called segmental NF1 when clinical features are limited to one area of the body.The study was carried out between October 1989 and December 1996 in the region of Oulu University Hospital (OUH) in northern Finland with a total population of 733 037 (31 December 1996).8The basic material consisted of families attending
Department of Clinical Genetics at the OUH for genetic counselling from 1982 onwards. Additional patients with a diagnosis of neurofibromatosis (International Classification of Diseases (ICD), 9th revision), diagnosis codes 2377A or 2251A, or neurofibromatosis (von Recklinghausen) (ICD, 8th revision) diagnosis code 74340, were traced from the records of the University Hospital and the four central hospitals in the area, two in Lapland, one in Kainuu, and one in central Ostrobothnia.Soft-tissue sarcomas, which result in approximately 10,700 diagnoses and 3,800 deaths per year in the United States1, show remarkable histologic diversity, with more than 50 recognized subtypes2.