Which finding is most characteristic of Neurofibromatosis type 1 (NF1)?

• A. Cafe-au-lait spots
• B. Bilateral acoustic neuromas
• C. Hyperextensible joints
• D. Retinal detachment

Answer: (A)

In Neurofibromatosis type 1, the most characteristic finding is multiple café-au-lait spots on the skin. These flat, pigmented macules typically appear in early childhood and, when present in quantity (commonly six or more) and of sufficient size, are a classic clue for NF1. They often appear along with other NF1 features such as axillary or inguinal freckling, Lisch nodules in the iris, neurofibromas, and potential optic pathway gliomas.

Bilateral acoustic neuromas point toward Neurofibromatosis type 2, not NF1, making that choice inconsistent with NF1. Hyperextensible joints and retinal detachment can occur in various conditions and are not characteristic hallmarks of NF1.