A 20-year-old patient has multiple café-au-lait macules, axillary freckling, Lisch nodules, and neurofibromata. He is at highest risk for which internal malignancy?

• A Optic pathway glioma (most common CNS tumor)
• B Pheochromocytoma
• C Malignant peripheral nerve sheath tumor (MPNST) ✓
• D Juvenile chronic myelomonocytic leukemia (JCML)

Explanation

Neurofibromatosis type 1 (NF1, von Recklinghausen disease; NF1 gene on chromosome 17q11.2 encoding neurofibromin, a RAS-GAP) carries the highest risk for malignant peripheral nerve sheath tumor (MPNST), which occurs in 8-13% of NF1 patients and carries 5-year survival of approximately 20-50%. While optic glioma is the most common CNS tumor in NF1, MPNST is the most life-threatening malignancy. JCML occurs in childhood NF1. Pheochromocytoma risk is elevated but less common than MPNST.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.