Table 2.

NF1: tumor features, with typical ages at presentation and childhood risk

Disease featureFrequency (pediatric risk) in %Age of presentation
SeriesHuson (15)McGaughran (16)Update for key tumorsa
Patients in series1355231,500
 Peripheral neurofibromas>9960 (20–60)≥7 years
 Plexiform neurofibromas
 All plexiforms3015 (15)0–18 years
 Large lesions of head and neck1.26 (6)0–3 years
  CNS tumors
 Optic glioma (symptomatic)1.55 (5–6)6%Childhood
 Other CNS tumors1.52.0 (1)2%Lifelong
 Spinal neurofibromas1.52.0 (0.2)0.2%Lifelong
Malignancy
 Malignant peripheral nerve sheath tumors1.55 (0.2)0.2%bLifelong
 Embryonal rhabdomyosarcoma1.50.2 (0.2)0.3%0–5
 Gastrointestinal tumorsc (neurofibromas and GISTs)2.22.0 (0)0%Lifelong
 Pheochromocytoma0.70.4 (0.2)0%≥10 years
 Duodenal carcinoid1.52 (0.1)0%≥10 years
 Glomus tumors in nail beds00.2 (0.1)0%Adults (usually)
  • Abbreviation: GIST, gastrointestinal stromal tumor.

  • aUpdate based on 1,500 NF1 patients in the Manchester register.

  • b0.5% by age 20 years.

  • cFrequency of GIST in adulthood has been found to be as high as 6%, but this may reflect MRI surveillance detecting asymptomatic tumors.