What Causes Severe Headaches?

Hi my son has been complaining of headaches for the past month. At one point he has one for 4 days straight and meds would not work. His dr requested a CT scan without contrast. They said they came back ok but when I just read the report I am concerned. It said: The ventricular system is prominent in size, but within the range of normal. The cortical sulci are within range for age. There are no intracranial mass lesions, and there is no mass effect or midline shift. No abnormal fluid collections are seen. No acute intracranial hemorrhage or areas of abnormal parenchymal density are identified. The basal cisterns are patent. A small, approximately 5 mm, pineal cyst is present (series 8 image 41). The visualized osseous structures are unremarkable. There is mucosal thickening throughout the ethmoidal and sphenoidal sinuses, with mild mucosal thickening within the visualized maxillary sinuses. Why was a cyst found in my sons brain not addressed and is this dangerous. and with his ventricular size being prominent...it concerns me. What do you think of these findings