Tarlov Cyst or TC

Tarlov cysts are also known as perineural/perineurial, or sacral nerve root cysts. They are dilations of the nerve root sheaths and are abnormal sacs filled with cerebrospinal fluid that can cause progressively painful radiculopathy (nerve pain). They are located most prevalently in the sacrum. The Tarlov cysts appear on MRI to be dilated or ballooned areas of the sheaths that cover nerve roots along the spinal column. The cysts are created by the dilated sheaths of the nerve roots directly connected to the subarachnoid area of the spinal column, through which the cerebrospinal fluid flows. Many people have Tarlov cysts visible on a MRI, but have experienced no relevant symptoms. The cysts are perhaps identified, but are not acknowledged as significant by the radiologist reading the films or by the physician who ordered them. If the patient has no symptoms that might be suggestive of symptomatic TCs, and sometimes even if they do have symptoms, the patient might not be told about the finding on the MRI. It is not unusual if the cyst has been present for a number of years to see evidence of erosion and remodeling of the sacral bone. When conditions cause these cysts to fill with spinal fluid and to expand in size, they begin to compress important surrounding nerve fibers, or the cysts may contain nerve fibers, resulting in a variety of symptoms including chronic pain.

TC is an abbreviation used by patients with Tarlov cysts, and is not a standardized medical abbreviation.