Abdominal Splenosis Mimicking a Colon Tumour.

Splenosis is a benign condition which results from the self-implantation of splenic tissue on intra or extraperitoneal surfaces, after splenic trauma or splenectomy. Patients are usually asymptomatic but may present with varied symptoms related to the implantation site. The diagnosis is a challenge because abdominal splenosis can mimic several diseases, including neoplasm. The gold standard examination for its diagnosis is scintigraphy with 99mTc-labelled heat-denatured erythrocyte. When splenosis is found in an asymptomatic patient, surgical removal is not indicated. A 57-year-old male patient presented with sporadic epigastric pain and a suspected mass in the recto-sigmoid transition. Abdominal ultrasound, CT and MRI identified this mass, its characteristics and location, but failed to distinguish its nature. However, given the patient's past history of splenectomy and because the mass showed a similar sign to that of the splenic parenchyma, a hypothesis of abdominal splenosis was raised, which was confirmed by scintigraphy with 99mTc-labelled heat-denatured erythrocyte. In this case, the diagnosis was obtained before the patient was subjected to more invasive procedures, which are associated with high morbidity, and, as in most cases, no targeted intervention was necessary. LEARNING POINTS: Increasing numbers of cases of abdominal trauma will result in more frequent splenosis.Diagnosis is sometimes complex as splenosis mimics several diseases.The usual complementary imaging studies often fail to diagnose this entity so clinical suspicion is fundamental for correct diagnosis and treatment. © EFIM 2021.