Hepatic splenosis is a rare entity which involves imbedding of native splenic tissue into liver parenchyma. This typically occurs after abdominal trauma, splenic laceration, or splenectomy. A 35 year old Russian male with history of obesity presented to Urology for evaluation given history of a solitary kidney. Urinalysis showed evidence of microhematuria and subsequent urine cytology showed a highly atypical cell. An abdominal MRI without contrast was done for further evaluation. A 3.4 cm x 5.0 cm T1 hypointense, T2 hyperintense mass in the right hepatic lobe was seen (figure 1). Additional history revealed splenectomy and nephrectomy after trauma in 1984. He denied blood transfusions, intravenous drug use, or sexual promiscuity. He admitted to a 6 year period of heavy alcohol use in his twenties. Labs revealed normal LFTs and negative viral hepatitis B and C serologies. Tumor markers CEA, AFP, and Ca 19-9 were not elevated. An abdominal MRI with contrast was done to better evaluate the lesion. It showed an unchanged lobulated 3.4 cm x 5.0 cm mass in hepatic segment 8 with arterial enhancement and patchy areas of washout (figure 1). The differential included hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma, focal nodular hyperplasia, sarcoma, and metastatic disease from testicular cancer. There was particular concern for HCC given arterial enhancement with washout. An ultrasound guided biopsy was done for diagnosis. Pathology of the mass showed red and white pulp of splenic tissue surrounded by normal appearing hepatocytes (figure 2). Approximately 80% of patients with hepatic splenosis have a history of splenectomy. The interval time between splenectomy and hepatic splenosis is 25 years. The pathogenesis is believed to be from hematogenous spread or direct seeding of splenic tissue onto exposed serosal surfaces at the time of trauma or splenectomy. Technetium-99m-labeled heat denatured red blood cell scintigraphy or supraparamagnetic iron oxide enhanced MRI are non-invasive tests that can confirm the diagnosis. Hepatic splenosis does not require resection unless the patient has evidence of idiopathic thrombocytopenic purpura or autoimmune hemolytic anemia. Although hepatic splenosis is a rare entity, it can mimic malignancy and lead to invasive testing and surgery. It is important to consider this diagnosis in patients with history of splenectomy and characteristic imaging in order to prevent unnecessary medical intervention.2423_A Figure 1 No Caption available.2423_B Figure 2 No Caption available.