This case illustrates an incidental finding observed when assessing the brain in a stroke protocol 6 years ago. The patient does not have cancer history. 

The lesion has been followed up during this period and has kept stable appearance since then. MRI features are also compatible with a subependymoma: T1 homogenous and isointense to the white matter, T2 hyperintense to adjacent white and grey matter, and no contrast enhancement. 

Subependymomas are typically hypovascular well circumscribed masses attached to the ventricular wall by a narrow pedicle, and most commonly seen in the fourth ventricle, but can arise anywhere where there is ependyma.

This case is a presumptive diagnosis based on imaging findings and clinical history.