Table of ContentsDefinition / general | Sites | Clinical features | Radiology images | Case reports | Treatment | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Differential diagnosis
Cite this page: Shankar V. Plexiform neurofibroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissueneurofibromaplexiform.html. Accessed February 3rd, 2023.
Definition / general
- Benign peripheral nerve sheath tumor that surrounds multiple nerve fascicles
- Has irregularly thickened, distorted, tortuous structure
- Plexiform: complex; in the form of a plexus or network
- Orbit, face, neck, back, inguinal
- Almost always develops during childhood
- Large tumors are attached to major nerve trunks in neck or extremities
- 5% transform to MPNST, a higher rate than classic neurofibromas
- Part of diagnostic criteria for neurofibromatosis type 1 (NF1, Mod Pathol 1998;11:612), although isolated plexiform neurofibromas may occur without definitive evidence of NF1 (Laryngoscope 2004;114:1410)
- 27% of childhood neurofibroma patients had plexiform neurofibromas in one study (J Pediatr (Rio J) 2007;83:571)
- 5 year old boy with massive penile enlargement (Urol J 2007;4:52)
- 12 year old boy with facial plexiform neurofibroma (J Indian Soc Pedod Prev Dent 2007;25:30)
- 17 year old boy with plexiform neurofibroma of the submandibular gland and von Recklinghausen's disease (Rare Tumors 2011;3:e4)
- 19 year old man with diffuse plexiform neurofibroma of the back (Hawaii Med J 2010;69:191)
- Excision for symptomatic relief; often cannot completely excise the tumor
- Recurrence may occur even if completely excised
Contributed by R.F. Chinoy, M.D.
Contributed by Mark R. Wick, M.D.
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- Associated with grossly enlarged and tortuous nerves
- Deep tumors are often large
- Often resembles "bag of worms"
- Highly vascularized and locally invasive
Microscopic (histologic) description
- Nodular or diffuse
- Diffuse cases are also known as elephantiasis neurofibromatosa; characterized by an overgrowth of epidermal and subcutaneous tissue (Dermatol Online J 2009;15:7)
- Hypocellular with myxoid background; contains Schwann cells, fibroblasts and mast cells
- Occasional nuclear palisading
- Rarely is pigmented due to melanocytes (J Am Acad Dermatol 2007;56:862)
- No biphasic pattern of schwannoma
Microscopic (histologic) images