Neurofibromatosis 1: recognition and management of associated neuroblastoma.

Neurofibroma and neuroblastoma both arise from the neural crest, and there has long been speculation regarding a pathogenetic relationship between them. Clinical characteristics do not necessarily distinguish these tumors, therefore the diagnosis of neuroblastoma should be considered in all children with neurofibromatosis 1 (NF-1) who have a rapidly growing or inaccessible mass. A careful physical examination, imaging studies, and urinary catecholamine measurement are indicated. In a child with NF-1 and malignancy, direct tissue examination may be necessary to differentiate malignant from nonmalignant tumor and guide therapy. Furthermore, with the significantly increased risk of certain types of childhood cancer in these patients, we recommend evaluation for this common heritable condition in all patients with malignancy.