Right renal mass diagnosed as focal splenosis; a rare differential for a small renal mass highlighting utility of heat damaged Tc-99m RBC scintigraphy to avoid unnecessary surgery.

Small renal masses (SRM) represent a heterogenous group of kidney lesions that are often found incidentally and can represent a diagnostic dilemma. Herein, we report a 55 year old female who presented with a 25mm right renal mass. She had no symptomology or significant medical history but did report undergoing a traumatic splenectomy 30 years prior. Using Tc-99 m heat damaged RBC scintigraphy, the renal mass was confirmed as focal splenosis. Right sided renal splenosis is almost unheard of. Our case illustrates how good clinical history and correct imaging can prevent unnecessary investigations and surgery for a rare differential of SRMs.