Upper quadrant pain. Spleen borderline size 12.1cm, mild bilateral pelviectasis of kidneys. Minimal R-side hydronephrosis. Peripelvic cyst. Normal?

Probably. Pelviectasis is a general term used to describe dilation of the renal pelvis, or collecting system of the kidney and, generally, is clinically insignificant. Hydronephrosis also refers to dilation of the renal pelvis, But has the added connotation that the pathology was caused by an obstructive process, such as a kidney stone or in your case the peripelvic cyst of Rt kidney. Unremarkable finding.