Hippocampal hyperintensities are identified in 60%–80% of NF1 patients and have been linked to HS in NF1; however, they have not been observed in other HS cases.49-52 Lastly, we observed that NF1-associated HS is not linked with antecedent events, such as prolonged febrile seizures, which are commonly associated with HS. Here, NF1 is linked to histiocytic sarcoma.