Dear friends. This was a case where it really paid off to be a member of OCAD! (I know its free :-))
Many and great responses, all in favour of "Cystic adventitial disease" and maybe it is not the parameniscial cysts dissecting into the adventitia, but joint fluid along small vessels close to the joint. It is hard to see those small vessels on my study, but easy to imagine where they are supposed to be. Even if my idea of cysts compressing the vessel is correct, the diagnosis from you guys made me understand it better.
I got nice compliments on the image quality from several of you and also a copy of a presentation about the matter from Atul Taneja, thanks!
I will post this case on my instagram "mskradiologyno" later today to share – a cool diagnosis.
Have a nice day!
Best,
Roar
Here are some of the responses:
We think that just like with intraneural cysts of the peroneal nerve around the knee joint arise from joint fluid propagating from the knee joint just beneath the epineurium in the articular branch, that adventitial cystic disease also arises from propagation of joint fluid within the adventitial layer of an articular branch of the popliteal artery into the popliteal artery proper. The cysts then dissect in this layer with joint fluid as the source.
Looks like patient has two separate things going on. Has paramedical cyst but the cystic lesion encircling the popliteal artery is in my opinion adventitial cystic disease of popliteal artery and it is known to cause intermittent claudication of associated lower limb.
While this patient clearly has parameniscal cysts, could this instead be adventitial cystic disease in addition? I have seen a prox tib/fib ganglion appear to dissect into the tibial nerve, and the surgeon confirmed the findings, but maybe two separate diagnoses is the reality here?
Very nice case Roar! Thanks for sharing.I have seen a few cases, both on the knee but also on the wrist. I know this entity as Adventitial Disease of the Popliteal Artery, which was previously thought to be from vascular origin, but as MRI scanners have gained so much resolution over the time they showed that on most of the cases these cysts come from the joint (either parameniscal, or ganglion cysts).
Cool case, thanks for sharing. I’ve seen similar cases or variants of this and typically report it as cystic adventitial disease once there is involvement of/mass effect on the popliteal artery and a supportive clinical history. In my institution these go to vascular surgery (as opposed to ortho). I’ve also seen plenty of cases where the cyst might come close to popliteal artery but without actually involving the adventitia of the artery or mass effect, in which case I just call it a ganglion/synovial cyst in the pop fossa.
man. 18. sep. 2023 kl. 13:17 skrev Roar Pedersen <pedersen70>:
Dear friendsA young athlete in her twenties, presenting with numbness in left distal leg and foot after as short as a couple of minutes of running. Previously resected lateral meniscus, and the images show parameniscal cysts appearing to dissect into the soft tissues along the popliteal artery, actually partially surrounding the artery, raising suspicion of a popliteal artery entrapment syndrome. Cystic changes appear at 2 different locations, the distal maybe originating at or close to the proximal tibiofibular joint.
See how the left foot goes white after 60 seconds of jogging! (published with permission from the patient)
