M58, ct scan says "bilateral renal cortical cyst noted. the largest cyst at the upper pole of the left kidney measures 3.8x5 cm." is this significiant?

Probably not: The majority of people develop a few kidney cysts, especially by the time we reach your age. They are usually benign. A kidney ultrasound would better characterize if it is a simple cyst (benign) or not, especially if there was no IV contrast in the CT scan. It should be noted how many cysts were found, which was not apparent in your description, so I'm only assuming one on each kidney.