The relationship between neurofibromatosis type 1, juvenile xanthogranuloma, and malignancy: A retrospective case-control study.

Background: Neurofibromatosis type 1 (NF-1) predisposes individuals to the development of benign and malignant tumors. The association of NF-1, juvenile xanthogranuloma (JXG), and juvenile myelomonocytic leukemia has been described in the literature. It is unclear whether JXG alone constitute a risk factor for leukemia or other malignancies in children with NF-1.

Objective: To determine if there is an association between NF-1, JXG, and malignancy.

Methods: We conducted a retrospective case-control study comparing children with NF-1 and malignancy (cases) with sex- and age-matched children with NF-1 without malignancy (controls).

Results: We identified 739 patients with NF-1 over a 20-year period, 14 of whom also had a diagnosis of malignancy. These cases include 9 (64%) boys and 5 (36%) girls. JXG were found in 4/14 (28.5%) cases and 6/29 (21%) controls (odds ratio 1.5, 95% confidence interval 0.35-6.6, P = .56).

Limitations: Retrospective design, small number of cases, and inconsistent documentation of clinical findings, including age at disappearance of JXG.

Conclusions: Juvenile xanthogranulomas do not appear to confer an increased risk for malignancy in children with NF-1.