Pediatric neurosarcoidosis with cavernous sinus involvement and internal carotid artery stenosis.

Sarcoidosis is a rare multisystemic disease characterized by noncaseating granulomas. Pediatric-onset adult-type sarcoidosis is extremely rare, and neurological involvement is scarce in this population. Herein, we report on a 14-year-old girl presenting with headache, weight loss, lateral gaze palsy, and a long-lasting history of unilateral hilar lymphadenopathy. Erythroid sedimentation rate (42 mm/h) and C‑reactive protein (61 mg/L) were both elevated. Cerebrospinal fluid pressure was elevated (36 cm/H2O), and pseudotumor cerebri was suspected. Brain magnetic resonance imaging (MRI) showed an extra-axial dural-based lesion, extending along the right tentorium to the cavernous sinus, Meckel's cave, the dura of the middle cranial fossa, and the prepontine cistern. Given the substantial life-threatening risks associated with intracranial biopsy, tissue sampling was obtained from the right hilar lymph node. The biopsy revealed noncaseating granulomatous lymphadenitis. After excluding other diagnoses, including immunoglobulin G4-related disease, Wegener's disease, tuberculosis, lymphoma, or lymphohistiocytosis, we eventually established the diagnosis of sarcoidosis. The patient received systemic steroids and subcutaneous methotrexate treatment in the first line. Three months later, due to absence of lesion regression in MRI and the life-threatening potential of the lesion, we initiated intravenous monthly infliximab. Radiological remission was achieved with three doses of monthly infliximab. Systemic steroids were tapered to 4 mg/day thereafter, and infliximab was continued bimonthly after six doses of monthly treatment. Systemic steroids were discontinued at the ninth month of treatment. The patient is symptom free and had no treatment side effects during follow-up.