Brain mri showed a tiny 4mmx3mm anterolaterally left sided cyst. what sort of cyst would this be called, rathke cleft cyst, arachnoid cyst etc? which?

Brain Cysts: Hi, This depends entirely on the exact/precise location of the cyst ("Anterolateral" is too broad of a region), as well as the "radiographic characteristics", such as density, illumination with MRI weighting, smoothness of borders, etc. Generally, with cysts that are this size, we also look to see if there are prior studies to compare to determine what the diagnosis may be.