cortical neoplastic or dysplastic focus is possible?

Our son (7 years old at the time) had a possible stroke in November 2000, but too many doctors, many opinions...we were left out in the cold (information wise).  This past week, we had a neurology appointment to discuss our son

[CCF-Neuro-M.D.-SH]

First of all, keep in mind that I am unable to diagnose you because I am unable to examine you, this forum is for educational purposes.      
   The impression that you have reported from the 2005 CT scan suggests that there is an area of the brain in the right frontal lobe (underneath the forehead on the right) that has abnormal signal characteristics.  The possibilities for this area of abnormal signal include: 1. An old stroke (but the radiologist suggests that it does not have the typical appearance one would expect for a stroke (encephalomalacia)). 2. A tumor (neoplastic process) meningiomas are often found in this location (close to the interhemispheric fissure), but other tumors are also possible (the good news is that it has not grown in 5 years since a note was made that there was no change since the previous scan in 2000- which would suggest a slow growing/benign tumor if it is a tumor). 3. Cortical dysplasia (a dysplastic focus) is a disorganized area of cortex (brain) that is dysfunctional and can often give rise to seizures.  From your description, it sounds like the fellow was describing your sons echocardiogram and the absence of a PFO (patent foramen ovale- or 'hole in the heart').  A PFO can be associated with strokes in some patients.  The abnormal signal area found on the right side of your sons brain is not easy to define based on a CT scan.  I would recommend getting a MRI scan with GAD contrast to further define the lesion (especially given the radiologists concern about a possible tumor).  
I hope this has been helpful.