Analysis of Extramedullary Erythropoiesis in the Spleen by a Semiquantitative Method Using Indium‐111

Abstract
A semiquantitative method for evaluating the splenic uptake of 111In is described. The uptake of In in the spleen was significantly higher in 7 patients with exttrmedullary erythropoiesis (EME) than in a control group of 7 patients with comparable degrees of splenomegaly but without clinical and/or histological signs of EME. The discrimination between these groups could be improved by taking the degree of splenomegaly into account. The described technique is a valuable non-invasive aid for establishing the presence of EME in the spleen. [This technique could be useful for the diagnosis of myeloproliferative diseases.].