Soft tissue
Peripheral nerve
Neurofibroma
Neurofibromatosis type 1
Author: Vijay Shankar, M.D.
Topic Completed: 1 November 2012
Minor changes: 15 September 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Neurofibromatosis type 1 [title] soft tissue
Table of Contents
Definition / general | Clinical features | Clinical images | Differential diagnosisCite this page: Shankar V. Neurofibromatosis type 1. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissueNF1.html. Accessed May 15th, 2021.
Definition / general
- Also called von Recklinghausen disease, NF1
- Defect in neurofibromin gene at 17q11.2; protein is widely expressed tumor suppressor gene that downregulates p21 ras oncoprotein; highest levels in neural tissue; gene has numerous sites of mutation; variable phenotypic expression
- 1/3000 individuals, 50% from autosomal dominant inheritance, 50% are new mutations
- Adrenomedullin (ADM) is serum biomarker of NF1 (Clin Cancer Res 2010;16:5048)
Clinical features
- Multiple neurofibromas (plexiform, solitary); plexiform are relatively specific
- 6 or more cafe au lait spots over nerve trunks, 1.5 cm or larger (cafe au lait spot: increase in melanin in epidermal basal layer, may overlie a neurofibroma, smooth delicate margins; solitary café au lait spots are normal)
- Lisch nodules (pigmented iris hamartomas, 94% by age 6)
- 2 - 4x increased risk of other tumors (childhood CML, ganglioneuroma, meningioma, pheochromocytoma, rhabdomyosarcoma); 5 - 13% develop MPNST; also acoustic neuroma (schwannoma), astrocytoma, gastric carcinoid, GIST, glomus tumor, lipoma, optic nerve glioma, Wilm tumor (Hum Genomics 2011;5:623)
- Nontumors: congenital malformations, fibrosing alveolitis, megacolon, skeletal lesions (30%-spinal deformities [kyphoscoliosis], bone cysts)
Clinical images
Images hosted on other servers:
Cafe au lait spots
Differential diagnosis
- Albright's syndrome: polyostotic fibrous dysplasia of bone, patchy dermal pigmentation, endocrine dysfunction
