Review Question - QID 106525

This patient has Neurofibromatosis type I (NF1). While dermal neurofibromas are characteristic of NF1, optic gliomas are another complication.

NF1 is an autosomal dominant neurocutaneous disorder classically characterized by the presence of numerous dermal neurofibromas, café-au-lait spots, and pigmented iris hamartomas (Lisch nodules). NF1 is caused by a mutation in the NF1 gene, located on chromosome 17. Optic gliomas and pheochromocytomas are also associated with NF1.

Stulberg et al. highlight the importance of early evaluation of congenital hyperpigmented skin lesions for disorders, such as Neurofibromatosis type I, that would warrant additional follow up. Café-au-lait macules are often found on the trunk and may extend several centimeters. In isolation, the presence of café-au-lait macules may be benign. However, in occurrence with other findings, such as axillary or inguinal freckling, iris hamartomas, or distinctive osseous lesions, café-au-lait macules can be diagnostic of NF1. The presence of a family history of NF1 would also be suggestive of this diagnosis.

Lee describes the progress and management of optic pathway gliomas as in patients with NF1. Optic pathway gliomas are often asymptomatic, though depending on their location they may cause vision loss, retroorbital pain, proptosis, or (rarely) death. Optic pathway gliomas are monitored clinically and with serial MRIs. Treatment with chemotherapy or radiotherapy is only indicated with the presence of symptoms or tumor growth. Resection is performed in severe cases.

Figure A shows numerous dermal neurofibromas. Illustration A shows pigmented iris hamartomas, also known as Lisch nodules. Illustration B shows a "café-au-lait" spot.

Incorrect Answers:
Answer 1: Bilateral acoustic schwannomas are a complication of neurofibromatosis type II.
Answers 2, 5: Cardiac rhabdomyomas and renal angiomyolipomas are seen in tuberous sclerosis.
Answer 4: Retinal hemangioblastomas are a complication of Von Hippel-Lindau syndrome.