Incidental Pineal Cysts: Is Surveillance Necessary?

ObjectiveThe natural history of incidental pineal cysts is poorly understood. Neurosurgeons and neuroradiologists are more frequently faced with this disease in the advent of higher-resolution magnetic resonance imaging (MRI) scanning. We aim to suggest a suitable surveillance strategy for these patients.MethodsAll patients who had MRI of the brain between June 2007 and January 2014 (n = 42,099) at The Walton Centre for Neurology and Neurosurgery were included. Radiologic reports containing the terms "pineal" and "cyst" were reviewed to identify patients.ResultsA total of 281 patients were identified with pineal cysts. The principal indication for head MRI was headache (50.2%), although no symptoms were deemed attributable to pineal disease. A total of 178 patients (63.3%) were female, and the age at diagnosis ranged from 16 to 84 years. The median size of pineal cyst at diagnosis was 10 mm. A total of 181 patients had subsequent follow-up at a median time of 6 months (range, 1-68). Eleven pineal cysts (6%) changed size during the follow-up period. Four patients had a reduction in cyst size; the median change was 2.5 mm. A further 7 pineal cysts increased in cyst size; the median change was 2 mm. No patients developed complications.ConclusionsIncidental pineal cysts typically show a benign course. In the adult population, they do not require long-term neurosurgical follow-up, because pineal cysts tend to remain a stable size. In asymptomatic patients, we recommend a single follow-up MRI scan at 12 months to confirm diagnosis. The patient should then be discharged if the cyst remains stable