PVNS: experience and causes

Has anyone heard a definition or read a distinction between localized and diffuse PVNS tumors? I assume just by the names of the 2 versions of this that diffuse means these tumors occur multiple times in different place, and localized means they are singular, in one place.

Thanks for your help

wp4934 I discussed the differences with my consultant from a treatment point of view, after i researched it myself and understood the differences from treatment/prognosis prospective... I was diagnosed with localised PVNS and initially told it would be relatively straightforward to treat, with arthroscopic surgery. It turned out, that I needed open-surgery and synovectomy. Whether that was to minimise the risk of it coming back, or because the area was more wider affected than first thought, I don't know. But the surgeon and consultants changed their treatment after the biopsy results at the last minute.

There seems to be some confusion online about which is the rarer form of PVNS and how rare it is, I've seen conflicting data which may be due to the sources/different countries and lack of a universal understanding of the disease still. I've read that localised is more rarer affecting about 1 in 9 million people, but also seen reports suggest the diffused form is rarer (perhaps they mean where it affects more than one joint).

The key difference from what I've read and my understanding is, that the diffused version has the potential to not only affect an entire joint site, but also can be more prolific and can spread throughout the body to other joint sites in some cases. It's therefore more difficult to treat and has a higher likelihood of returning than the localised version which is often (but not always) limited to one specific small area of a joint, and so easier to treat with less invasive surgery.

You can have multiple tumours and multiple affects (in the same joint) and still have a localised PVNS diagnosis, even though it appears you have two or more different affected sites (as in my case, front/side and back of the knee joint).

I'm no doctor and only going by what I've read and discussed with my consultant to surmise, but think the actual diagnosis of localised v diffused is a clinical diagnosis based on the extent of the cells affected in the joint.. if it's uniformly affected right across the joint area, then it's diffused, whereas if some areas appear normal and it's one or more localised/contained sites are affected, then it's localised and hasn't spread to the entire joint. I've read that in localised PVNS its more common to see the tumour-like growths (my consultant said they're not actually tumours like cancer, but rather more like cysts and harmless, unless they increase in size and affect the bone), whereas in diffused you may not see any tumours but may have more swelling over the joint area, perhaps more periods of pain and limited movement since the entire joint is affected.

One thing I do know, as you pointed out..a common theme in both diffussed and localised PVNS, is that the symptoms in terms of pain and limited mobility can come and go from day to day or week to week.. you may feel ok and other days you may really be suffering. That's why it's often misdiagnosed as arthritis which is similar, symptoms wise. The tell tale sign with PVNS is any joint swelling or tumours protruding..even tumours at the back of the joint can be mistaken for Baker's Cyst (as in my case). All these misdiagnosis can delay treatment and cause the disease to progress further.. I think X-Ray and/or MRI scan should be standard early procedure where a person presents with any arthritis-PVNS like symptoms, particularly after any trauma or injury to the joint which again seems to be a common theme in the development of PVNS in patients.

So little is fully understood about this disease due to lack of clinical research and clinical trials (probably due to so few people affected by it worldwide) that still many questions remain unanswered.. it was though to be a type of cancer originally until around the 1950's I believe. It does have many characteristics of a cancer and in some ways is more prolific and difficult to treat than some cancers I think (at least the diffused type).

There was a clinical study and report carried out in UK in 1970's with PVNS patients in UK I think (I don't have a link for it handy, but I'm sure it won't be difficult to find on Google).

The hospital where I was treated (Birmingham Royal Orthopedic) treat about only a dozen cases of PVNS every year the surgeon said..and of those, the majority are patients from outside the UK on a private-patient basis. Royal Orthopedic is considered one of the UK and world's leading orthopedic hospitals, so that's give some idea how rare this disease is.

Thanks for your help.

I am 69 years old and have a history of knee problems since a bad injury playing football when 36. I have had four arthroscopic surgeries to remove bone fragments and torn cartilage over the years, the last three years ago. I was diagnosed with Chondro Calcinosis, caused by depositions of calcium pyrophosphate dihydrite crystals in the soft tissues. I went for a total knee replacement on 10th July. When opened up it was discovered that I had diffuse PVNS ( somewhat outside the normal age range) which was excised before the knee was replaced. In my physio class, all other patients have good range of movement in their knees, while I can neither straighten nor bend to 90degrees.

As a result I went back into hospital for two days last week to undergo manipulation under anaesthesia and two days on a bend/stretch machine. The knee is still stiff and painful after 12 weeks. I hope to get back to competitive tennis and wonder if anyone has a time frame for recovery from the two procedures.

I posted in August after hearing I was diagnosed with PVNS. Since they changed my diagnosis a couple of times and now are unsure what I have. The doctors wanted to treat me for arthritis with chemo type drugs, without really knowing what was wrong with me. I chose to have the surgery and clean out the synovial fluids and test what was removed. The pathology reports showed negative for cancer, gout, arthritis. But what they found is something my doctors have never seen. They found thousands of crystals described as calcium phosphate crystals. What is odd is that they found no inflammation or white blood cells. Surgery was they only way to remove these crystals as my body was not breaking them down and steriods and anti-inflamitory drugs were not working.

Now I am recovering from the surgery in my third week and my range of motion is better every day. Still cannot fully bend or put any weight on the knee (Crawl) posting again to see if anyone else has had problems like mine.

Want to share my experience and see if i can get any tips for what i can expect in the coming months.

I am a 27 yr old male hailing from the southern land of the commonwealth and coming from a land that only houses around 23 million people the discussions on this rare disease is unsurprisingly slim.

I was diagnosed with the localised form of PVNS (the surgeon referred to it as "focal nodular PVNS") and the MRI scans showed a single large tumour like growth in the medial aspect of the Hoffa's fat pad and was beginning to press up against the femur. 8 days ago i had a knee arthrotomy to get the tumour removed and now am the proud owner of a 13cm long scar down the front of my knee. The surgeon had remarked that my case was the largest tumour of this form he had seen, roughly the size of "a testical" (his words).

8 days on i am still walking around on crutches however with my post-op coming up in a few days i'm a little concerned about my range of motion. At the moment the most i can bend the knee is roughly 80* and that's putting up with quite a bit of pain and significant feelings of tightness around the joint. My quad muscle only responds minimally and i'm constantly popping pills to stave off the ever present soreness in the entire limb. At this stage in the recovery should i be expecting more and how long should any additional processes take afterwards?

hi, i'm new to this condition and was diagnosed about a month ago. i have been doing lots of reading up on the condition and i feel i don't fit into some of the categories as i'm not the usual age because i'm 19 when a lot of people are in their 30's or 40's when they are diagnosed.

i had an MRI scan to check for ligament damage after i fall i had. when the MRI results came back i was told i had a tumour and was referred to my nearest orthopaedic tumour unit. i was told that it was probably 'only' PVNS but would need a biopsy to be safe and make sure it was. after my biopsy i was then called back to the unit as they had sent the sample to several specialist hospitals and they couldn't diagnose but due to fast growing nature (which i believe is unusual in PVNS because its usually slow growing) and how rapidly it was changing they suggested it may be a cancerous tumour and needed to be remover that next week. i didnt realistically have the luxury of considering the treatments as i was facing having cancer and was told i would need this operation. i had my operation in September and 2 days after the consultant looking after me came round and told me it was great news, it wasnt cancer it was 'only' PVNS. they then went on to tell me i didnt actually need the big operation and that they couldve done a 'simple' key hole procedure. so now i am stuck trying to get back to full walking again, and am unable to do simple things i used to do such as bending my knees, from a procedure i apparently didnt actually need. the fact that for a week, i believed i had cancer seems to bypass people and they seem to overlook the how my head has been completely fried by the experience. i am wondering if anybody else has had a similar experience to that because people expect me to be overjoyed i dont have cancer but dont grasp fully why i feel angry about it all!

Oh meg, that sounds awful thinking you had cancer and having to endure open surgery unnecessarily.

I also went several months believing I also might have had cancer and prepared for the worse when I felt big lumps at the back of my knee. Sure it's a relief knowing its not cancer, but as for Dr's implying PVNS is lesser, that's bizarre, in many ways it is very much like a form of cancer the only difference is it doesn't kill you (they thought PVNS was cancer in the early days). Perhaps the lack of knowledge about this rare condition makes them think because it's not malignant and no threat to life, people should be glad. I had the same experience as you, at the biopsy a doctor happily saying "it's ok it's not malignant, it's PVNS" with a smile. I looked at him emotionless and in dread (knowing what PVNS was and having researched it well and read treatment, recovery time, and high return rate) he repeated.. "it's not malignant" and waited for me to acknowledge.

However, as anyone knows with PVNS its a real problem that impedes on your life, even after surgery. In 50% of cases its actually WORSE than cancer for many people. The 50% return-rate (and how fast that happens, often in 12 months or less) makes PVNS a real drag and much more difficult to treat, especially for younger people like yourself with knee replacements are out of the question. If you're in the 50% return group you might have radiotherapy sessions like a cancer patient and further ongoing surgery, the only upside is no chemo.

I know one woman who has had 10 (yes TEN) surgical procedures (including several rounds of radiotherapy) to try and eradicate it from her knee only for it to keep returning within a year, and she was only in her 30's. They reached the end of the line with her eventually and said there's nothing else they can do but manage it with pain relief if it returns again until she's old enough for a knee replacement.

Like yourself, I've had my open surgery and I've done my physiotherapy now and regained my muscle strength from everything they took away. But my knee is numb (I'm told the nerves sensation may never return) and I'm nowhere near back to the level of mobility I was before I had PVNS. I can walk ok and I'm pain-free thankfully, but running is impossible (and I used to love to jog 2 miles a day), bending to a squat or kneeling position is impossible for anything more than a few seconds, else it's very painful.

Note: interesting again how you had a trauma injury prior to the onset. That seems to be a common theme that I see again and again.. I'm wondering if PVNS is trigged by some kind of defective auto-immune response to damaged tissue.

Meg, did you read alice56's story? She's only 18 and has PVNS and its maybe ended her dancing career ambition. As you say, it's unusual for young people to get this condition its normally people middle aged. It's worrying if this condition is starting to affect younger people, because of the complications in treating it and how it can impede lifestyle and career choices.

Eulogy: I expect you're more reassured after having your post-op by now? What you describe with the very limited mobility post-op and pain, is entirely normal. I myself was in same position (and also have a nice 13cm scar down my knee!), thinking "oh hell, what have they done to me, I was better off before the surgery..will I ever right, and how long will it take?!" It does get better and you'll feel loads of improvement to mobility and the pain will be gone once you get through the recovery phase. I don't know if you're having physiotherapy (I had 2 months of it) they tell you it's important to do it and to keep pushing the joint motion and activity a bit further gradually with progressively difficult stretching exercises.

I think after the operation a lot of stiffness and pain is just the bodies response to what's been done in surgery, so don't worry that it's been a failure or not worked.. it will take anything from several weeks (it was over 2 months in my case) after surgery until you feel the affects of the surgery gone and fully recovered. Then you'll be able to tell if it's been successful.

I still have my tumour-like growths (or "nodular cysts" as the surgeon calls them, seems they all have different names for them!) at the back of my knee. They're protruding slightly when the leg is straight, and I think they prevent me squatting or bending the knee fully. Yet the surgeon says he's not intending to remove them oddly, unless they cause pain or return of PVNS symptoms i.e. joint stiffness and/or swelling. Maybe because they're at the back he doesn't feel they pose any risk to the bone like in your case. I've been told I'm to be monitored though regularly by the hospital with regular checks and scans to pick up any changes.

As a quick update to anyone who has been following my progress.. it's now been almost 4 months since I had open surgery on my left knee. I have my final physiotherapy session in December, which is more of a sign-off session after a final consultation with the surgeon in December also, to determine what happens next.

I don't expect to have further surgery or treatment at this stage, but it's a possibility as I still have the nodular cyst growths, and they do cause pain and stiffness that lasts into the next day, if I attempt a squat position or bending.

I'm greatly improved though from where I was though before the surgery. I'm walking absolutely fine without a stick, and I'm pain-free which is a great blessing. I can now lift 1.25kg weight on the leg (12 reps x 2 sets daily) on my weights bench and the muscle strength is returning but it's a slow process..I used to be able to do 20kg!

Next month will be the real test I think to see if I can do running and cycling once my muscular and knee strength is fully returned, or whether these nodular cysts are a lifestyle impeding thing that have to be dealt with surgically. The surgeon is not keen to remove them for some reason (even though it seems relatively straightforward with key-hole surgery). Maybe it's because it's too close to the open-surgery and he would prefer to wait a year or so, or maybe he thinks it may cause the affected cells to spread or something.

I'm not sure. I'll find out in December and do a final update.