Medical Student Research Forum Posters

Neurofibromatosis type 1 (NF1) is an inherited tumor syndrome caused by heterozygous germline mutations in the NF1 gene, occurring in approximately 1/2600 individuals. A subset of patients with neurofibromatosis type 1 (NF1) develop juvenile xanthogranulomas (JXGs), a non-Langerhans cell histiocytosis, and some of these patients also develop juvenile myelomonocytic leukemia (JMML).Yet, these associations are poorly delineated.JXG is a benign proliferation of non-Langerhans cells histiocytes characterized by small yellow/brown papulonodules ranging from 1-20 mm in size. JMML is a mixed myeloproliferative-myelodysplastic disorder that affects children, most often before age 6.4. The first and only systematic review on this described therisk of developing JMML 20 to 30 times higher in patients with NF1 with JXG lesions compared to those without JXG. Since then, mostly isolated case reports have either refuted or confirmed this triple association.