Neurosarcoidosis Pathologically Diagnosed Via Biopsy of a Normal-Sized Inguinal Lymph Node With Fluorodeoxyglucose Accumulation on Positron Emission Tomography/Computed Tomography in a Patient With a History of Brain Ewing's Sarcoma.

Neurosarcoidosis is a rare disease and is often difficult to diagnose. Herein, we report a case of neurosarcoidosis in a patient with a history of Ewing's sarcoma of the brain. He presented with fever of unknown origin, and a pathological diagnosis was obtained via biopsy of a normal-sized inguinal lymph node with fluorodeoxyglucose (FDG) accumulation on positron emission tomography/computed tomography (PET/CT). The condition could not have been diagnosed without FDG-PET/CT.