cyst behind knee

A few months ago we noticed a cyst behind our son's knee.  We told our dr. about it at the time, he was not concerned.  We brought it to his attention again a few weeks ago b/c the cyst is persisting - he then had us do an ultrasound.  We had the ultrasound today and the technician - although she could not give us a report stated that it was a water filled cyst which she also mentioned is usually nothing to be concerned about.    We will get a complete report next week.  She mentioned that the concern may be to figure out why the water is present.    I know that this does not seem like a big deal, but since my son's thalassemia diagnosis I get concerned about everything.    Does anyone have an idea as to why this may occur?  Andy, could this be related to thalassemia or to the use of prednisone? 

Thank you all, and I will let you know what the doctor tells us next week.  I hope that it is really nothing to be concerned about. 

Sharmin

Hi Sharmin

So sorry to hear about this, but i am sure that it will be nothing to be concerned about. Sorry i don't have much information to help you but you will be in my prayers and thoughts. Wish you all the luck
Manal

Hi Sharmin,

This sounds like a Baker's cyst. Your doctor can verify if it is and will tell you if any treatment will be necessary. They usually disappear within two years.

From http://www.nlm.nih.gov/medlineplus/ency/article/001222.htm

Baker's cyst is a fluid collection behind the knee. This cyst may be formed by the connection of a normal bursa (a normal lubricating fluid sac) with the knee joint. This type is more common in children.

The condition can also be caused by the herniation of the knee joint capsule out into the back of the knee, which is more common in adults. This type of Baker's cyst is commonly associated with a tear in the meniscal cartilage of the knee...
Often no treatment is necessary...A Baker's cyst is a benign lesion that will not cause any long-term harm

Treatment is often with anti-inflammatory drugs. Prednisone may have a positive effect on the cyst over time.


I will mention the following because it can be significant in terms of thal patients. It must be verified that a swelling like this is indeed a cyst and not a DVT (deep vein thrombosis). Thals do have clotting issues at times (one more reason to supplement with vitamin E, which is a blood thinner) so a blood clot or DVT should be ruled out in thals, as they can be life-threatening.

It is very important to tell the difference between a ruptured Baker's cyst and a blood clot (deep venous thrombosis), which can also cause pain, swelling, and bruising on the back of the knee and calf. A blood clot may be dangerous and requires immediate medical attention.

Sharmin, I will assume that the technician who did the ultra sound would know the difference between a cyst and a blood clot in an ultrasound, so I doubt this is any danger here.

Hi Andy,
Our doctor mentioned 'Baker's cyst' when he examined our son.  Thank you so much for your reply, I feel a lot better, I was a little scared this morning.   
There is not pain or discomfort associated with the bump, and the technician did say that it was a cyst filled with water.  The lump is not obvious - my mom, who has x-ray vision, noticed it while my son was putting on his hockey equipment, I probably would not have noticed it. 
Once again I am amazed with how much knowledge you have - I would like to put in another vote for the honorary doctorate. 

I would like to begin the vitamin E supplement - how much would one give a 53lb child? 
I am also not giving him any other supplements - such as folate - b/c I don't know how much to give.

Thanks again Andy,
Sharni

Hi Sharmin,

I hope everything is going well with your son,Andy's answer must have helped you,as always ,he is genious,

Wishing you luck an joy,

ZAINI.

Thank you Zaini and Manal - I do feel better - I hope your kids are well!   

Hi Shirmin,

My sister had one on the back of her hand/wrist. It was exactly like you said. The doctors suggested removing the water via syring. She didn't go for that and she used the Homeopathy medicine and the cyst was cured in few months.

Thanks Sajid, do you know what medication your sister used? 
I will let you all know what the doctor tells us next week. 

Thanks again Andy and all of my friends!   

Hi Sharmin,

I would suggest 100 IU daily of vitamin E complex. Best results come with using the complex which is a mix of tocopehrols. Natural E is superior to synthetic so look for d-alpha and not dl-alpha tocopherol. 500-1000 mcg (micrograms) of folic acid daily would be sufficient at his age. Some adult majors take as high as 10 mg daily.

As far as the Baker's cyst, it may possibly be related to his athletics, as they are common among athletes. Again, this would be nothing to be concerned about, especially if it causes no pain. Painless cysts are usually allowed to resolve on their own.

Thanks again Andy - we will be going in for a transfusion tomorrow - at that time the doctor will share the results of the ultrasound with us and let us know what is going on & what his action plan is.  So far everything he has said has been in line with what you are saying. 

I will share the results with you also I will share his ferritin levels.

Sharmin

... Yes it is a Bakers Cyst.. and it could also burst some day.. But nothing serious.. and since it is filled with water.. if it bursts.the water will  make the feet swell a lot , and it could be painfull.. for a few days.. then ani-biotic and a pain killer is usually prescribed.. and he will be okay in a few days..

 I am saying this from my own experience.. and the symptoms... that is, if the cyst bursts... could be like , as if a blood clot is causing the swelling.. but a Doppler Test would confirm, that it is the water collection from  the cyst..
Most times it will not burst...

Shikha

Thank you Shikha.  Yes, the doctor also believes that it is a baker's cyst.
We had transfusion day today.  The doctor had not yet received the ultrasound results, nor did he have the ferritin.  The cyst seems to have shrunk (it was barely detectable), the doctor believes it is because my son has not played any sports for the past few weeks.  He did say that once he receives the results he will refer us to a specialist to determine whether it needs to be drained. 

Thank you all for your concern and help,

Sharmin

Andy,

Your reply on the canker sore reminded me of my son's issue with the Baker's cyst - which we determined was related to his athletics (in his case hockey and soccer inflates them and when he is not playing they shrink.)  It is funny when I read your response and then go to our pediatrician and get the same response after a thorough investigation.  Surprisingly, you are able to diagnose things without even seeing the patient!  I was quite amazed by this today!  I wonder sometimes, is there something that you don't know?   

Sharmin

Sharmin, i totaly agree but we have to touch wood

manal

ya me too agree frns,
and we are very lucky..
Thank you Andy.