Leucoerythroblastic refers to an abnormality in blood cell formation that results in the presence of both immature white blood cells and red blood cells in the bloodstream. Synonyms for this term include leukoerythrocytosis, myelophthisic anemia, and extramedullary hematopoiesis. These conditions can be caused by a variety of factors such as bone marrow disorders, infections, or cancer. Symptoms of leucoerythroblastic conditions include fatigue, weakness, pallor, and an enlarged spleen. Diagnosis typically involves a blood test and bone marrow biopsy. Treatment may involve addressing the underlying cause of the condition and managing symptoms with medication and blood transfusions.