The Symptoms
It was late in 2012, I felt that my knee cap was moving out of place occasionally when I walked. This started happening frequently. One morning when I woke up I felt a sharp pain on my right knee just below the knee cap towards the left side. The pain subsided in about 10 minutes after a vigorous rub to the affected area. I walked normally that day. A couple days later, I was working in my office. When I got up from my chair, I felt a sharp and terrible pain on my right knee and it was as though my knee was giving away and my leg would collapse in the wrong direction. I rushed home and scheduled an appointment with the local doctor for the next day. I biked back home and walked to the clinic which was two streets away from home. I had pain all the while I walked and it turned unbearable on my way back. However, I was able to bike more than comfortably. When I was back home, I noticed that there was a huge swelling on top my right knee.
First visit to the doctor
I visited the doctor the next day. He performed some tests to diagnose the condition of my knee. He said my knee was stable, but wasn’t sure what caused the pain and the swelling. He wanted me to wait for a couple of days to see if the swelling subsided. He also advised me to take pain killers if that helped reduce pain.
Second visit to the doctor
I visited the doctor again in a couple of days. In the meantime I researched online to find ways to reduce pain. I started applying ice packs and kept my leg raised over a pillow. The ice pack only stiffened my knee. I continued with it for a while to help any internal injury to heal. On my second visit, the doctor still wasn’t sure about the reason for the swelling and the pain. So he suggested I go for an X Ray and Ultrasound scan of the affected area.
After a wait of about a week, I had my X Ray and Ultrasound done. Five days later, I visited the doctor again to learn about the results.
Third visit to the doctor
Fortunately, the X Ray was normal and there was no damage to the bones. The Ultrasound said there was lot of fluid, but was inconclusive on the cause of pain. The doctor advised me to go for an MRI scan. I had to wait for about 2 weeks to get my MRI done.
First MRI Results
A week after the MRI, my doctor called me to discuss the MRI results. He told me that I had a rare disease called Pigmented Villonodular Synovitis (PVNS). He told me not to worry as the tumor was benign and not malignant and also it was localized and was not going to spread like cancer. He also suggested I go in for another MRI, this time with a contrast agent injected, so that he can confirm PVNS. He also fixed up an appointment with a Orthopedic specialist.
Second MRI Results and Ortho Visit
Ten days after my second MRI, I visited the specialist. He told me that PVNS was confirmed and it has to be treated with surgery. The size of the tumor was 9.4 x 15 x 17mm and it was present behind Hoffa’s fat pad. He also told me that the causes for the disease were unknown and hence no medication exists. He suggested I go in for an open synovectomy and advised that I do it as quickly as possible. This is what the second MRI report said
The mass in the joint of the dorsal fat pad of Hoffa shows hemosiderin artifacts and there is strong staining of the synovium of the knee. The image fits best with PVNS
MRI showing localized PVNS on right knee
I was living abroad and working on a contract. It was impossible for me to take a month off and go in for surgery. So, I decided to wait and review the condition after I return home.
Nine months later…
Nine months later, I returned to my home country and headed straight to hospital. I must mention that in these 9 months, I had no great pain but slight discomfort for a couple of times which lasted for about 4 – 5 days. The doctor had a look and ordered an MRI. The MRI report came in the same afternoon and the existence of the lesion and PVNS was confirmed. Luckily, it had not grown much and the size remained almost the same. The size mentioned in this MRI was 1.4 x 0.7 cm. The report said
Small circumscribed hypo-intense lesion interposed between Hoffa’s fat pad and femoral condyle – suggestive of localized nodular synovitis (localized pigmented villonodular synovitis)
With that, I was recommended to go in for surgery to remove the lesion. A couple of days later, I underwent an arthroscopic procedure to remove the lesion and was out of hospital in two days.
Post surgical recovery and biopsy
The removed lesion was sent for biopsy as I recovered from surgery. Right after the surgery, my leg was swollen just above the knee. I was prescribed pain killers, antibiotics, anti platelets and some vitamin tablets. I was also advised to apply ice pack every 3 hours. My knee was stiff and applying ice pack only increased the stiffness. I was also asked to do some exercises to improve muscle strength and improve circulation.
Ten days later, I had the stitches removed. My leg is a still stiff but I have regained about 50% of my normal action and I am able to climb stairs with both legs with some support. The swelling and stiffness still persist. Keeping the leg raised has helped reduce the swelling to a large extent.
Meanwhile, the biopsy report has come in.
Thin layer of synovial lining cells and underlying Stroma with diffuse fibrosis. Scattered pigmented macrophages are seen. Giant cells or foamy macrophages are not present
When I went in for review, a surgeon raised the specter of PVNS turning to cancer. The earlier diagnosis clearly said that was not the case. The absence of giant cells in the biopsy report is another positive point. I am waiting for some questions to be answered and am also seeking second opinion in this regard. I will post and update once I have a confirmation.
There is not a lot of online literature on PVNS, let alone localized PVNS. I hope this helps someone who is looking for information or someone who has gone through localized PVNS to provide me tips on what I should watch out for. If someone has had localized PVNS and got it treated, I would like to know if there was a recurrence and how you feel after the treatment.
B Space 
Thank you for sharing your story with us. I am also auffering from PVNS since last 3 years
Hi Bala, hope you are well and in the best of health. Can you please let me know how your recovery was post the PVNS surgery and whether or not you had any further relapse of PVNS. I would really appreciate as my brother is due for a surgery in 4 to 5 weeks time.
Hi Moaz, thank you, I am doing fine. Luckily, there has been no relapse of PVNS on my knee. Good luck to your brother with the surgery.
Thanks so much for your story! I was diagnosed yesterday and head into surgery in 4 weeks. Do you have any update?
Well, it is almost 5 years post surgery for me now and so far so good. Good luck with your surgery
Hi, Bala
I was diagnosed with pvns last two weeks and my situation similar to you, but my pvns is behind of my left knee. I really want to know after the surgery can we do exercise and slow running like before? I’m 26 and I can’t imagine life without the sport. Many thanks.
Hi Zhang,
Absolutely. After surgery and a bit of physiotherapy I was able to get back to normal life. Good luck!
Hi glad to see from the comments you recovered well, I’m in the UK and had pvns diagnosed behind my right knee, almost 2 weeks post operation I still have very little motion in my knee joint, I am wondering if you had similar issues or did you have full motion much quicker?
I was able to walk in a couple of days post surgery, though the stiffness lasted a while. Good luck with your recovery
mine also ve pvns 6mm……my doctor sait we can wait until pain araise……wat i ve to do
I am surprised you don’t have pain at 6 mm. I had extreme pain for much smaller size. Unfortunately, there is nothing much we can do about it. Good luck with your treatment.
Have been diagnosed for PVNS yesterday. Doc wants to take it out in 10 days. Ready to do so as I have felt my kneecap catch and lock which disallowed me to fully extend the knee, for a little over a year.
.. Though, I must say it is truly a blessing to know a reason behind the inability to do a normal body function, and to have a reason behind the pain!
The funny part is that my doctor was the same doctor who I have had previously, who has worked on this same knee,3 years ago, and he recalls seeing the body in my knee and was unsure of the body and had observed it and left it in caution, though not focused on it as the surgery was to focus on stabilizing my knee to stop ongoing kneecap dislocations… CRAZY> This was probably the cause of all of my problems ALL ALONG.
..At least I believe this will be the end of my knee pain.
Thanks for the post as I felt aware of a lot of your symptoms as well.
Sorry to hear and good luck with the surgery.
In June 2020 during a physical therapy session, my leg locked and I could not move. I was in severe pain and could not walk, bend or straighten my leg. I went to a pain management doctor and he drained my swollen knee and gave me a shot of cortisone. He removed 4 vitals of fluid/blood. A few days later the knee swelled up again and no relief from the cortisone. My knee kept locking and I had severe pain. A week later I had an MRI and it showed bleeding inside the joint, however, the doctors could not figure out the problem with my knee. Because this is a rare disease, doctors don’t typically look for PVNS. A Meniscus tear is mostly like what they are looking for, as in my case. It was really my call to do surgery because I had my knee drained twice in a few weeks and I was in severe pain. I know I needed to find out what was causing the swelling and pain. Localized PVNS was confirmed. I started physical therapy 3 weeks post surgery. It is now going on 7 weeks post surgery. Some days are better than others. My knee is improving, but I cannot cross my leg, and still have limited bending. Climbing stairs is challenging and causes pain. I do hope I have 100% recovery.
Good luck with your recovery. I can understand the “some days are better than others” perfectly well. I had the same experience as well. 100% recovery is definitely possible even if it takes a bit of time. It is almost 7 years now post surgery for me and I am doing great and there are no signs of it coming back. Also, I moved to a warmer place which helps.
This is encouraging to hear since I am in early recovery. I knew something was wrong and did not agree with the doctor at first to put off surgery. I am happy to hear you are doing well 7 years later. My PVNS was in the front and behind my knee. It is nice to connect with others who have experienced PVNS, especially since it is rare.
Indeed, you made the right decision to go ahead with surgery. Putting it off would have meant more pain and not to mention more damage to the knee. The reason I wrote this blog post was because this disease is rare and not well known even in the medical community and there is very little literature about it which is publicly available.
We as usual I’m a bit different. I have PVNS in my elbow. It has taken months for diagnosis and the pain is terrible. I am seeing a surgeon this week and hopefully will have something done soon. This is causing pain in both hand and shoulder of my right arm making it difficult to do the simplest things.
Good luck!
I have found most doctors have little knowledge if any about PNVS. I will be having an MRI of my jaw for possible PNVS. Having a lot of pain on the side of my face and unable to bite and chew properly. The maxillofacial surgeon I met with 2 weeks ago told me found PNVS in a man’s jaw recently. I was happy she was familiar with PNVS. If I do have PNVS this would be my second round PVNS in a different joint.
Good luck! PT will keep after your surgery. Please send an update.