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Date of last update: 10/09/2017.

Forum Name: Miscellaneous Nephrology Topics

Question: Cyst on left kidney - pain on right side - why?

 Mt Moose - Sun Jul 11, 2010 2:42 pm

I am a 59 yr old male in good health. In March 2009 I had a kidney stone and an ultra sound was done. No cyst at that time. Now, 16 months later I went to the doctor because of the persisting pain in the area of my right kidney. The ultra sound showed a 6.5cm mass on the bottom of my left kidney. I have a CT Scan and MRI scheduled for this week.
My question is why is the pain on my right side when the mass is on my left? The pain is pretty constant ranging from 4 to 8. I also have bone spurs growing in my lower spine. I thought that the pain was from the spurs.

What are the chances of this cyst being cancer?
If it's not cancer what could it be?

Thank you.
 Dr.M.Aroon kamath - Mon Jul 19, 2010 8:20 am

User avatar Hi,
You have not mentioned a few important details...
- on which side was the stone which was discovered earlier?
- what happened to that stone? Was it seen during the latest ultrasonographic examination?

Also what is not clear from your history is whether what was discovered was a cyst or a mass.

When a cyst is discovered on imaging, the crucial question that arises is whether it is a simple, benign cyst or is it a cancer? Bosniak's Classification of Cystic Renal Masses into four classes, lends help in this regard.

Cysts of any Bosniak class,
if symptomatic,
will need a CT and should be seen by a urologist.

If asymptomatic,
- Bosniak class 1 cysts(simple cysts): will need only to be observed and CT if symptoms occur.
- Bosniak class 2 cysts(probably benign): preferably renal CT every 6-12 months.
- Bosniak class 3 cysts(indeterminate): renal CT/MRI/possible surgery.
- Bosniak class 4(presumed malignant cyst) : as for class 3.

There are many causes of solid masses and malignancy is of overriding concern.

Your right sided pain in the right loin may be
- related to your spinal problem(radiculopathy) or
- may be related to the kidney stone identified in the past(if it had been present in the right kidney).This stone could have moved down and perhaps started to cause a problem now.
- or some other cause.

You need to keep in touch with your urologist as you are symptomatic.Renal stone as a cause of this pain needs to be excluded.Helical CT is of value in this regard.
Best wishes!

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