Cytogenetics of neurofibromas: two case reports and literature review.

Only a few karyotypes of neurofibromas have been documented in the literature. In this report, we describe two new cases in which conventional cytogenetics demonstrated the presence of abnormal clones. Combining karyotypes of the nine previously reported cases, we found that the most frequent structural rearrangements involved chromosome 9p. Including the two cases reported here, 5/11 cases involved 9p, and four of these involved the 9p21 approximately p22 region.