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Case 1:- Neurofibromatosis type 1
- 1a,b: Café-au-lait spot 2:iris Lisch nodules
- sphenoid bone hypoplasia and buphthalmos
Case 2: - Right optic nerve glioma
- Neurofibromatosis type 1 is diagnosed only when two or more criteria from the following group of seven are met:
- Six or more café-au-lait spots > 5 mm in diameter in prepubescents or 15 mm in diameter in postpubenscents
- Two or more neurofibromas of any type or one plexiform neurofibroma
- Freckling of axillary, inguinal, or other intertriginous areas.
- Optic nerve glioma
- Two or more iris Lisch nodules
- A distinctive osseous lesion, such as, sphenoid bone dysplasia or thinning of the long bone cortex, with or without pseudarthrosis
- A first-degree relative with NF1, according to the above-mentioned criteria
Neurofibromatosis type 1 (NF1) also known as von Recklinghausen disease, manifests characteristic lesions composed of melanocytes or neuroglial cells, which are both, primarily, derivatives of neural crest mesenchyme.
Neurofibromatosis type 1 is a familial disorder, inherited as an autosomal dominant disorder. The genetic locus of NF1 is on the long arm of chromosome 17 (17q11.2). The general features include multiple fibromas, pigmented skin lesions, osseous malformation, and associated tumors.
Neurofibromas are histologically benign and may take the form of either fibroma molluscum or plexiform neurofibromas. They may involve the eyelid, the face, and occasionally cause marked deformities. Lisch nodules are pigmented iris hamartomas present in 94-97% of the patients with NF1, who are over the age of six years.
Other ocular manifestations include congenital glaucoma and retinal astrocytomas. Osseous defects commonly involve the greater wing of the sphenoid, but may involve the orbits also. Multiple tumors of the brain, spinal cord, and meninges, as well as cranial, peripheral, and sympathetic nerves may be encountered in these patients. Optic nerve or chiasmal glioma in children is frequently associated with neurofibromatosis. These lesions cause proptosis and visual loss, but are rarely life threatening. Treatment for these lesions is controversial.
Legends
Figure 1: Four-year-old child with right eye proptosis, (a) Café-au-lait spot (case 1), (b) Café-au-lait spot (case 1)
Figure 2: Iris lisch nodules (case 1)
Figure 3: Computed tomography of head and orbit (case 1)
Figure 4: Café-au-lait spot (case 2)
Figure 5: Magnetic resonance imaging of the brain and orbit (case 2)
