Diffuse compensatory extramedullary hematopoiesis is well known to involve the spleen and liver in certain hematologic disorders. Hematopoietic tumor masses occasionally form and usually occur paraspinally in the posterior mediastinum. A 31-year-old patient with thalassemia is described with a massive, solitary, intrahepatic hematopoietic tumor and a smaller one in the posterior mediastinum. Review of the literature indicates that presentation as a large, focal liver lesion is unique. The implications and differential diagnosis are discussed.