MRI growth patterns of plexiform neurofibromas in patients with neurofibromatosis type 1

Abstract

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder with an incidence of 1:3000. Approximately 30% of NF1 patients develop plexiform neurofibromas (PNF) which often cause severe clinical deficits. We studied the growth patterns of 256 plexiform neurofibromas (PNF) by magnetic resonance imaging (MRI) and associated disfigurement and functional deficits to determine whether there are definable growth types of these tumors. Retrospectively, we evaluated MRI scans obtained during 1997 to 2003 of 256 plexiform neurofibromas from 202 patients with NF1. Clinical investigation was carried out at the same time as the MRI scans. We identified three growth patterns: superficial in 59, displacing in 76, and invasive growth in 121 tumors. The majority (52%) of invasive PNF were found in the face, head and neck area. While superficial PNF primarily caused aesthetic problems, displacing PNF led in most cases to aesthetic problems and pain, while invasive PNF led mainly to functional deficits and disfigurement. Our study demonstrates that PNF have different growth patterns that are associated with specific clinical features. Classification of PNF may open new opportunities in clinical management, especially regarding decisions and options associated with surgical intervention.

Clinical and genetic aspects of neurofibromatosis 1

“…1 Several different kinds of neurofibromas exist, but their classification is controversial. 1,[11][12][13][14] Neurofibroma formation is most common in the skin but may affect virtually any organ in the body.…”

Common Pediatric Head and Neck Congenital/Developmental Anomalies

“…7). 28,29 Neurofibroma differential considerations are broad and depend on location. Within the neuroforamen, neurofibroma, schwannoma, or potentially meningioma should be considered.…”

“…By far the most common 2 imaging diagnoses that neuroradiologists encounter are neurofibromas (including plexiform neurofibroma) and optic pathway gliomas. 27,28 Neurofibromas present as circumscribed, dumbbell-shaped, or spindle-shaped masses centered within the neuroforamen or along peripheral nerves ( Table 7). If present within a neuroforamen, there may be associated expansion of the foramen.…”

Multimodal Imaging in Neurofibromatosis Type 1-associated Nerve Sheath Tumors

“…They expand over the length of a nerve, are rich in extracellular matrix and can exhibit infiltrative growth ( • " Fig. 2) [22,23]. As a result, they can cause pronounced symptoms through compression or destruction of neural structures [6,23].…”

“…2) [22,23]. As a result, they can cause pronounced symptoms through compression or destruction of neural structures [6,23]. A focal malignant transformation into a malignant peripheral nerve sheath tumor can occur within a plexiform neurofibroma.…”