Clinical course of vestibular schwannoma in pediatric neurofibromatosis Type 2.
OBJECTIVE
Neurofibromatosis Type 2 (NF2) is an autosomal-dominant inherited disease, characterized by multiple neoplasia syndromes, including meningioma, schwannoma, glioma, and ependymoma. In this report, the authors present their clinical experience with pediatric NF2 patients. In particular, they focused on the clinical course of vestibular schwannoma (VS), including the natural growth rate, tumor control, and functional hearing outcomes.


METHODS
From May 1988 to June 2012, the authors recruited patients who were younger than 18 years and fulfilled the Manchester criteria. In total, 25 patients were enrolled in this study. The authors analyzed the clinical course of these patients. In addition, they measured the natural growth rate of VS before any treatment in these children with NF2. Then, they evaluated the tumor control rate and functional hearing outcomes after the treatment of VS.


RESULTS
The mean age at the onset of NF2-related symptoms was 9.9 ± 4.5 years (mean ± SD, range 1-17 years). The mean age at the diagnosis of NF2 was 12.9 ± 2.9 years (range 5-17 years). The mean follow-up period was 89.3 months (range 12-311 months). As initial manifestations, nonvestibular symptoms were frequently observed in pediatric patients with NF2. The mean natural growth rate of VS was 0.33 ± 0.41 cm(3)/year (range 0-1.35 cm(3)/year). The tumor control rate of VS was 35.3% at 3 years after Gamma Knife surgery (GKS). The actuarial rate of useful hearing preservation was 67% in the 1st year and 53% in the 5th year after GKS.


CONCLUSIONS
Clinical manifestations in children with NF2 were highly variable, compared with their adult counterparts. The natural growth rate of VS in children is slow, and this oncological feature may explain the diverse clinical manifestations besides vestibular symptoms in children with NF2. The treatment outcome of GKS for VS in children with NF2 was not favorable compared with previous reports of affected adults.
Departments of Neurosurgery and.
Jung Won
JW
Choi
Ji Yeoun
JY
Lee
Ji Hoon
JH
Phi
Kyu-Chang
KC
Wang
Hyun-Tai
HT
Chung
Sun Ha
SH
Paek
Dong Gyu
DG
Kim
Sung-Hye
SH
Park
Seung-Ki
SK
Kim
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing; D034381:Hearing Loss / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008499:Medical Records; D016518:Neurofibromatosis 2 / Q000150:complications* / Q000503:physiopathology; D009464:Neuroma, Acoustic / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery*; D018579:Patient Selection; D011859:Radiography; D016634:Radiosurgery; D012189:Retrospective Studies; D016896:Treatment Outcome
CNS = central nervous system; GKS = Gamma Knife surgery; Gamma Knife surgery; NF2 = neurofibromatosis Type 2; PNS = peripheral nervous system; PTA = pure tone audiometry; ROI = region of interest; VS = vestibular schwannoma; growth rate; neurofibromatosis; oncology; pediatric; schwannoma