Multiple Ectopic Splenic Masses after Rupture of Splenic Nodular Hyperplasia in a Dog

An 11-year-old Labrador retriever presented with loss of appetite, lack of activity, and hematuria for 1 week. The dog had undergone splenectomy because of rupture of splenic nodular hyperplasia 4 years ago. Abdominal ultrasonography revealed several masses of unknown origin in the abdominal cavity. The dog also had systemic inflammatory response syndrome, possibly due to cancerous or purulent peritonitis. An exploratory laparotomy was performed immediately, and revealed multiple masses on the greater omentum and the abdominal wall, accompanied by purulent inflammation. Most of the masses were surgically removed, and all surgical specimens were histologically diagnosed as ectopic spleen. The purulent peritonitis was considered more likely to be associated with urogenital infection rather than the ectopic splenic masses; the ectopic splenic masses were likely to be incidental, and might have been caused by the past rupture of splenic nodular hyperplasia. The possibility of ectopic splenic masses should be considered in patients with abdominal masses of unknown origin, especially those with a history of splenic rupture.