Perirectal intraperitoneal splenosis: A case report of MRI with laparoscopic correlation

Splenosis is a benign acquired condition, which appears after rupture of the spleen and heterotopic auto-transplantation. Mostly found as an incidental finding on cross-sectional imaging, definitive diagnosis is frequently made histologically after resection or tissue sampling. We report a case of a 36-year-old male patient who presented with increased susceptibility to infections, chronic fatigue, and a history of traumatic splenic rupture. Cross-sectional imaging showed perirectal formations within the mesorectal fascia, and extraperitoneal splenosis was suspected. Due to the radiologically unclear entity of the masses, diagnostic laparoscopy with tissue sampling was performed. Intraoperatively the masses turned out to be intraperitoneal. Histological workup showed splenic tissue, consistent with intraperitoneal splenosis after splenic rupture. In this article we want to discuss important imaging findings and their differentials, as well as clinical implications for this rare entity.