2021 年 98 巻 1 号 p. 156-158
Splenosis is an ectopic growth of splenic tissue disseminated by splenectomy or trauma. We report a case of splenosis occurring in the pelvis and diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). The case was a 52-year-old man with a past history of splenectomy and left nephrectomy due to traffic trauma. Abdominal computed tomography revealed a 38-mm mass lesion on the left side of the rectum. Endoscopic ultrasonography was performed, and a mass with a well-aligned margin and uniform hypoechoicity was found outside the rectum. EUS-FNA was performed. Pathological results showed a collection of lymphocytes and erythrocytes with no atypia. A diagnosis of splenosis was made.