Presentation
Knee pain.
Patient Data
Parameniscal cyst arising from the anterior root lateral meniscus with fluid signal extending to the anterior cruciate ligament, which is intact and without further ganglion cyst or frank mucoid degeneration. Adjacent Hoffa fat pad edema. Anterior root attachment is high signal. No findings of a meniscal tear elsewhere. No meniscal body extrusion.
Case Discussion
Parameniscal cysts are highly associated with meniscal tears except at the anterior lateral meniscus, where the association is less strong. This is thought to be due to the intimate relationship between the footplates of the anterior horn lateral meniscus and the anterior cruciate ligament and that some "parameniscal cysts" in this location are related to ACL mucoid degeneration and are actually ganglion cysts. While there is no frank mucoid degeneration the cyst pedicle can be tracked back to the ACL and the distal ACL is a little high signal.