Acquired pelvic splenosis in a pediatric patient with inflammatory bowel disease: A rare case report.

Splenosis is an acquired condition in which splenic tissue becomes implanted and grows in abnormal locations within the body, usually after the spleen has been injured or surgically removed. It is often discovered incidentally due to its asymptomatic nature. We report a rare case of asymptomatic pelvic splenosis in a 16-year-old female with a history of splenectomy for sudden splenic infarct at age 3 and inflammatory bowel disease diagnosed at age 15. Magnetic resonance enterography revealed a solid pelvic mass concerning for malignancy, prompting further evaluation with technetium-99m-labeled heat-denatured red blood cell scintigraphy. Imaging confirmed ectopic splenic tissue in both the pelvis and near the cecum. This case underscores the diagnostic challenge splenosis presents, especially in pediatric patients, due to its rarity and radiologic resemblance to neoplastic processes. It also highlights the critical role of nuclear medicine in avoiding unnecessary surgical interventions. Increased clinical awareness is essential for accurate diagnosis and appropriate management of this uncommon entity.