Types of neurofibromas and neurofibromatosis (NF1, NF2), diagnostic criteria, ophthalmologic findings, and related genetic diseases

 

Neurofibromas are benign peripheral nerve sheath tumors, commonly associated with Neurofibromatosis Type 1 (NF1) and Type 2 (NF2), which are multisystem genetic disorders with distinct clinical and ocular features.

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🔹 Neurofibromatosis Type 1 (NF1)

• Incidence: 1 in 2,600–3,000 births
• Main features: Skin lesions, peripheral nerve tumors
• Diagnosis (≥2 of NIH criteria):
   1) ≥6 café-au-lait macules
   2) Axillary/groin freckling
   3) ≥2 neurofibromas or 1 plexiform type
   4) Optic pathway glioma
   5) ≥2 Lisch nodules (iris hamartomas)
   6) Bone dysplasia (e.g., sphenoid wing)
   7) First-degree relative with NF1
• Ocular signs: Optic glioma, Lisch nodules, RPE hamartoma, retinal astrocytoma

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🔹 Neurofibromatosis Type 2 (NF2)

• Incidence: 1 in 25,000 births
• Main features: Multiple intracranial and intraspinal tumors
• Diagnosis (any 1 of the following):
   1) Bilateral vestibular schwannomas
   2) Unilateral schwannoma + NF2 family history
   3) NF2 family history + any two of: meningioma, glioma, schwannoma, cataract
   4) Multiple meningiomas + unilateral schwannoma
   5) Multiple meningiomas + any two of: schwannoma, glioma, cataract
• Ocular signs: Posterior subcapsular cataract, epiretinal membrane, optic sheath meningioma

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📋 NF1 vs. NF2 Comparison Table (English)

CategoryNF1NF2

Incidence	1 in 2,600–3,000 births	1 in 25,000 births
Main Involvement	Skin, peripheral nervous system	CNS tumors (vestibular, meningioma, glioma)
Diagnostic Criteria	≥2 NIH features	1 major criterion
Hallmark Signs	Skin spots, neurofibromas, Lisch nodules	Vestibular schwannomas, meningiomas, cataracts
Ocular Findings	Optic glioma, Lisch nodules, retinal lesions	Posterior cataract, ERM, optic sheath tumors