Clinical and Sonographic Classification of Neurofibromas in Children with Neurofibromatosis Type 1 – A Cluster Analysis

Abstract

Abstract Purpose High-frequency ultrasound allows the accurate identification of neurofibromas in neurofibromatosis type 1 (NF1). This study aimed to analyze the ultrasound features of neurofibromas in children with NF1, to establish a classification based on the clinical and sonographic patterns of the different types of neurofibromas, and to evaluate the interobserver correlation coefficient (κ) of this classification. Materials and Methods In this prospective, single referral center observational study, clinical and ultrasound findings of neurofibromas in children diagnosed with NF 1 were analyzed. To identify the ultrasound patterns, a cluster analysis allowing the inclusion of both clinical and ultrasound data was designed. The κ coefficient was calculated using 9 external evaluators. Results 265 ultrasound scans were performed on a total of 242 neurofibromas from 108 children diagnosed with NF1. Cluster analysis allowed the identification of 9 patterns (Snedecorʼs F, P < 0.001) classified as “classic” cutaneous neurofibroma, blue-red neurofibroma, pseudoatrophic neurofibroma, nodular subcutaneous neurofibroma, diffuse subcutaneous neurofibroma, congenital cutaneous neurofibroma, congenital plexiform neurofibroma, congenital diffuse and plexiform neurofibroma, and subfascial neurofibroma. The κ coefficient of the interobserver ratings was 0.82. Conclusion Patterns identified in the cluster analysis allow neurofibromas to be classified with a very high interobserver correlation.