The detection of extramedullary hematopoiesis in a patient with osteopetrosis

99mTc-HSA millimicrospheres were used to detect a site of extra medullary hematopoiesis in the chest of a patient with severe osteopetrosis, anemia, thrombocytopenia and splenomegaly causing renal complications. These problems led to the consideration of splenectomy which necessitated a search for other extra medullary hematopoietic sites.