Juvenile xanthogranuloma as a potential early manifestation of neurofibromatosis type 1: A case report.

RATIONALE: Juvenile xanthogranuloma (JXG), the most common form of non-Langerhans cell histiocytosis, typically presents in early childhood and often resolves spontaneously. Due to its generally favorable prognosis, physical examination may be overlooked. However, JXG has increasingly been associated with neurofibromatosis type 1 (NF1), highlighting the need for comprehensive evaluation.

PATIENT CONCERN: The patients were 14-month-old twin toddlers who presented to the outpatient clinic with multiple yellow papules on the scalp, first noted 2 months prior.

DIAGNOSIS: Physical examination revealed multiple yellow papules on the scalp, with dermoscopy showing the characteristic "setting sun" sign. Additionally, 10 to 20 café-au-lait macules of varying sizes were observed on the limbs and trunk. Genetic testing confirmed a mutation in the NF1 gene. Based on these findings, a final diagnosis of JXG associated with NF1 was made.

INTERVENTIONS: Comprehensive tests, including complete blood count, liver and kidney function tests, lipid profile, ophthalmologic screening, and brain magnetic resonance imaging, were performed on both patients. All results were unremarkable. Given the self-limiting nature of scalp JXG, no specific treatment was initiated, and regular follow-up was arranged.

OUTCOMES: At 1-year follow-up, one twin developed a biopsy-confirmed plexiform neurofibroma and is scheduled to begin selumetinib therapy. The other twin remains asymptomatic under close monitoring.

LESSONS: Patients with JXG, especially those under the age of 2, should undergo a thorough physical examination to evaluate for NF1.