A 10-year-old boy is brought with extensive café-au-lait macules (>6 macules, each >1.5 cm), axillary freckling, and two cutaneous neurofibromas. Slit-lamp examination reveals Lisch nodules. The diagnosis is NF-1. Which feature, if present, would indicate the HIGHEST immediate risk warranting urgent neuroimaging?
- A Plexiform neurofibroma overlying the orbit ✓
- B Macrocephaly and short stature
- C Learning difficulties and ADHD features
- D Increasing number of new café-au-lait spots
Explanation
Plexiform neurofibroma involving the orbit (periorbital/orbital plexiform neurofibroma) carries the highest immediate risks: proptosis, orbital deformity, visual impairment from amblyopia, and increased risk of malignant peripheral nerve sheath tumor transformation. Optic pathway gliomas occur in 15-20% of NF-1 patients and are associated with periorbital plexiform neurofibromas and visual pathway involvement — warranting urgent MRI brain and orbits. Macrocephaly and learning difficulties are common but not immediately dangerous. Progressive increase in CALS in childhood is normal. Plexiform neurofibromas are also a contraindication to prophylactic nerve-sparing surgery without imaging guidance.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.