Experimental subcapsular hematoma of the spleen: natural history and radioisotope scan correlation.

An experimental model was developed in dogs to correlate radioisotope scan findings of iatrogenic, in vivo, splenic injury with the natural history of the injury as determined by the clinical course and both gross and microscopic observations. It was found that small subcapsular injuries do not appear as discrete focal defects on scanning as do larger injuries; however, both small and large injuries cause an increased uptake of the radioactive colloid and increased clearing from the blood. In no dog did the subcapsular injury lead to delayed rupture, bleeding, or cyst formation, and all injuries healed by scarring and thickening of the overlying capsule. This study suggests that the entity of delayed rupture of the spleen in humans is, in fact, delayed diagnosis and not delayed bleeding.