The pedicle in neurofibromatosis.

Three cases of von Recklinghausen's disease (neurofibromatosis) are described, one with agenesis of a pedicle, another with multiple hypoplastic pedicles, and a third with bilateral hypoplastic pedicles producing a spondylolistesis. These peidcle deficiencies are manifestations of mesodermal dysplasia. Agenesis of the pedicle most likely represents a defect in chondrification. Hypoplasia probably represents a partial lack of development of the pedicle and the ipsilateral arch. Hypoplasia or agenesis of a pedicle should suggest the possibility of underlying neurofibromatosis.