Acquired pure red cell aplasia (PRCA) is a bone marrow disorder characterized by a reduction of red blood cells (erythrocytes) produced by the bone marrow. Signs and symptoms may include fatigue, lethargy, and/or abnormal paleness of the skin (pallor) due to the anemia the caused by the disorder. In most cases, the cause of acquired PRCA is unknown (idiopathic). In other cases it may occur secondary to autoimmune disorders, tumors of the thymus gland (thymomas), hematologic cancers, solid tumors, viral infections, or certain drugs. Treatment depends on the cause of the condition (if known) but often includes transfusions for individuals who are severely anemic and have cardiorespiratory failure.