Is there any harm to eat cooked renal pelvis in lamb kidney? I googled many forums listed in google and found people just say that cooked renal pelvis in lamb kidneys are stringy and chewy. That sounds to me like people already consider its edible, but it's somewhere where urine goes through, at least before it's getting into the urinal for the lamb. I am a bit concerned if this is cook-able and edible directly without any cleaning procedure.

I wonder if eating renal pelvis has any harm at all? If it's edible, is there any cleaning we should always do before cook it?
Nothing unhealthy if you eat it.  Just a aesthetic preference since it is a different texture than the body of the kidney.  If you don't get it all cut out when dressing the kidneys, it's kind of like eating rubber bands.  I prefer to cut it out with all of the bits of kidney fat.