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. It is typically associated with tumors of neural derivation. Plexiform neurofibromas are considered the prototype of the plexiform pattern 1.
- 1. Abbas O, Bhawan J. Cutaneous plexiform lesions. J. Cutan. Pathol. 2010;37 (6): 613-23. doi:10.1111/j.1600-0560.2010.01529.x - Pubmed citation
- 2. Prada CE, Rangwala FA, Martin LJ et-al. Pediatric plexiform neurofibromas: impact on morbidity and mortality in neurofibromatosis type 1. J. Pediatr. 2012;160 (3): 461-7. doi:10.1016/j.jpeds.2011.08.051 - Pubmed citation
- 3. Laffan EE, Ngan BY, Navarro OM. Pediatric soft-tissue tumors and pseudotumors: MR imaging features with pathologic correlation: part 2. Tumors of fibroblastic/myofibroblastic, so-called fibrohistiocytic, muscular, lymphomatous, neurogenic, hair matrix, and uncertain origin. Radiographics. 29 (4): e36. doi:10.1148/rg.e36 - Pubmed citation
- 4. Slam KD, Bohman SL, Sharma R et-al. Surgical considerations for the familial cancer syndrome, neurofibromatosis 1: a comprehensive review. Am Surg. 2009;75 (2): 120-8. Am Surg (link) - Pubmed citation