- Benign tumor of nerve sheath origin
- Most common in young adults
- May arise on any area of the skin
- Presents as a polypoid or nodular lesion
- Usually solitary, but multiple lesions are seen in neurofibromatosis type I, in which ordinary neurofibromas are the most common, but plexiform neurofibromas are nearly pathognomonic
- Cured by simple excision, with rare recurrences
- Malignant transformation occasionally occurs.
- Relatively well-circumscribed dermal or subcutaneous lesion
- Composed of a loose proliferation of spindle cells with wavy nuclei in a fibrillar, collagenous or myxoid stroma
- Scattered inflammatory cells, including mast cells
- Hyalinization of the collagen may sometimes occur.
- Mitotic activity in a neurofibroma in a patient with neurofibromatosis type I is considered evidence of malignancy.
A variety of subtypes exist, which will be described under their respective headings.