Solitary neurofibroma is a localized neurofibroma which is usually not associated with neurofibromatosis.
Age: This lesion usually occurs between the ages of 20 and 30.
Solitary neurofibromas are papular, nodular or pedunculated lesions and
greyish white in colour. These painless , slow growing tumours are soft
in consistency. Usually there is no evidence of secondary degenerative
The lesion is
nonencapsulated ( schwannoma is well encapsulated) and circumscribed.
Note: Presence of mitotic activity in neurofibroma is indicative of
malignancy. (Mitosis is common in schwannoma).
-Cutaneous Lipomatous Neurofibroma: Read abstracts
-Collagenous neurofibroma - Thick collagen bundles are present in the matrix.
-Epithelioid neurofibroma - The tumour cells are rounded with eosinophilic cytoplasm. Read abstract
-Granular neurofibroma - The cells contain granular PAS positive, diastase resistant cytoplasm.
-Pigmented neurofibroma - Scattered tumour cells contain melanin pigment (S100 protein, HMB45 and Melan A positive).
-Dendritic Cell Neurofibroma With Pseudorosettes:Read abstract
Neurofibromatosis was described by von Recklinhausen in 1882.
Neurofibromas may arise in any part of the body including axilla, thigh, buttock, deep lying soft tissue, orbit, mediastinum, retroperitoneum, tongue, gastrointestinal tract.
There are 8 clinical subtypes:
NF-1: Classic von Recklinghausen's disease is inherited as an autosomal
dominant trait. The responsible gene (NF1) is located in chromosome 17.
NF-2: Central neurofibromatosis- Autosomal dominant disorder (alteration of a gene located in chromosome 22). Associated with acoustic neuroma and a range of neoplasms of the central nervous system. Cutaneous schwannomas may also be present.
NF-3: Characterized by combined features of NF-1 and NF-2.
NF-4: Characterized by diffuse neurofibroma and cafe-au-lait pigmentation. Other features of NF-1are not present.
NF-5: Segmental form of neurofibromatosis where the disease is restricted to one area of the body.
NF-6: Cafe-au-lait pigmentation is the only manifestation.
N-7: Late onset type.
N-8: Miscellaneous group
Age: Occurs between ages of 10-30 years.
Site: Head and neck area.
Clinical presentation: Plaque like elevation of the skin. On cut section, entire subcutis is thickened by firm greyish tissue.
Microscopic features : Poorly defined lesion with diffuse replacement of the dermis and subcutis by neurofibromatous tissue. It diffusely infiltrate subcutaneous fat. It does not destroy but envelops the normal structure. The matrix of the lesion is uniform consisting of fine fibrillary collagen. The Schwann cells have shorter and more rounded contour in diffuse neurofibroma. Clusters of Meissner bodies may be present. Occasionally multinucleate giant cells may be present.
Age: Usually occurs in children and young adults.
Site: Head and neck region
Clinical presentation: The expanded nerves form irregular, convoluted cords and nodules.
Plexiform neurofibroma is associated with hyperpigmented skin, thickening of soft tissue and hypertrophy of bone.
Nodules of tortuous, expanded nerve branches cut in various planes of
Axon- Neurofilament positive
D/D: Plexiform Schwannoma
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