Soft tissue sarcomas and central nervous system tumors in children with neurofibromatosis type 1.

Objects: We aim to evaluate the characteristics of pediatric patients with neurofibromatosis type 1 (NF1) who developed soft tissue sarcomas (STSs) and central nervous system (CNS) tumors that have been followed up in our center.
Materials and Methods: Medical records of children with NF1 were retrospectively analyzed.
Results: There were 78 patients who met at least two diagnostic criteria for NF1. The median age of patients was 10 years (0.5-18), and M/F ratio was 1.3. The prevalance of the optic glioma was 11.5% (n = 9), and one patient with optic glioma also had cystic astrocytoma, one patient had brain stem tumor, and one patient had a CNS tumor (without histopathologic diagnosis). Seven of nine children were ≥ 7 years old at the time of the diagnosis of optic glioma. Visual impairment developed in four patients, and two of them were treated with radiotherapy solely on the basis of evidence of clinical and radiological progression of the tumors. Four patients developed STSs. Two of them had malignant peripheral nerve sheath tumors (MPNST), and the remaining two had bladder rhabdomyosarcoma. Three of the four patients with STSs died with progressive disease.
Conclusion: The clinical course of malignancy in NF1 is often different from that of similar tumor types in the general population. Careful follow-up in patients with NF1 is required to enable the early diagnosis of malignancies, and the developments of new targeted therapies are needed for improvement of the outcome for patients of this group, especially with MPNST.