The patient is a 48 -year-old female with a history of Sjogren’s syndrome and new-onset seizures. A negative work-up included an unremarkable MRI. The FDG PET brain scan was able to identify focally increased FDG uptake in the right mesiotemporal lobe indicating the presence of focal acute inflammation that explained the patient’s symptoms. This finding prompted further work up which led to the patient’s diagnosis of a thymoma. The patient made a full recovery after the surgical removal of the thymoma.