Plexiform neurofibroma is a benign tumour of peripheral nerves (WHO grade I) arising from a proliferation of all neural elements, pathognomonic of neurofibromatosis type 1 (NF1). It involves single or multiple nerve fascicles that arises from major nerve branches.
Clinically, it presents as a subcutaneous mass which feels like a "bag of worms". Most of the time, it is a superficial cutaneous/subcutaneous lesion, but it can occur almost anywhere in the body. Symptoms may be related to local mass effect.
It is found in approximately 30% of patients with neurofibromatosis type 1. There is a risk of malignant transformation in 5-10% of cases.
Non specific infiltrative subcutaneous lesion.
Reported signal characteristics include:
- T1: hypointense
- T2: hyperintense +/- hypointense central focus (target sign)
- T1 C+: mild enhancement
On imaging consder
History and etymology
The term plexiform comes from the infiltrative growth pattern that, histologically, looks like a plexus or a network. Plex- originates from the latin verb plectere meaning "to plait" or "interweave".
It is typically associated with tumours of neural derivation. Plexiform neurofibromas are considered the prototype of the plexiform pattern 1.
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