7.2 cm x 7.3 cm seems awfully large, how worried should I be if this is a cyst?

For about the last 2 years I have been getting bad headaches just out of the blue. Tylenol or ibuprofen did nothing. Finally after complaining enough to my doctor and having other issues such as blurred vision, memory loss, etc he sent me for a CT scan. When the report came back it said: The septal structures of the brain are midline. There is an oval shaped low density lesion seen at the lower aspect of the right basal ganglia measuring 1 cm. It could be a prominent perivascular space or possibly a choroidal cyst. There is a prominent low-density structure seen just about the quadrigminal plate cistern in the region of the pineal gland. It measures 7.2 cm x7.3 cm in AP and transverse dimension. It may simply reflect a prominent CFS space. A cystic lesion involving the pineal glad cannot be excluded. Now I am waiting for an appointment for a MRI. 7.2 cm x 7.3 cm seems awfully large, how worried should I be if this is a cyst?