Incidental finding of intramural splenic heterotopy in the colon mimicking subepithelial neoplasm: a case report

The aim of this case report is describe an unprecedented case with histological and immunohistochemical diagnosis of splenic heterotopy in the colon using material obtained by endoscopic ultrasound-guided biopsy. Splenic heterotopia is a benign condition characterized by the implantation of splenic tissue in areas distant from its usual anatomical site, such as the peritoneum, omentum, mesentery, liver, pancreas, and subcutaneous tissue and, more rarely, in locations such as the colon and brain. It is generally associated with a history of splenic trauma or splenectomy and typically does not cause specific symptoms. A 35-year-old white male patient who was healthy, with no history of trauma or splenectomy, but had a family history of colorectal neoplasia underwent colonoscopy for screening. The examination revealed a large bulge in the proximal descending colon, covered by normal-appearing mucosa. Endoscopic ultrasound-guided puncture was performed with a 22 gauge fine needle biopsy, and the histopathological and immunohistochemical analysis results were consistent with a heterotopic spleen. This is the first report of a primary intramural colic splenosis case with histological and immunohistochemical diagnosis of splenic heterotopia in the colon, using material obtained by endoscopic ultrasound and ultrasound-guided biopsy.