Pathophysiology
1) pancytopenia in conjunctiojn with bone marrow hypocellularity 2) biphasic age at presentation – as young adult and in elderly
Signs and Symptoms
1) abrupt or insidious onset 2) bleeding, easy bruising, retinal hemorrhage 3) malaise/weakness 4) orthopnea 5) pounding in ears
Characteristic Test Findings
Laboratory – 1) anemia 2) low platelet count 3) neutropenia 4) increased MCV
Histology/Gross Pathology
1) bone marrow replaced by fat and fibrosis with < 1% stem cells present 2) large, scant RBCs 3) few reticulocytes
Associated Conditions
1) Fanconi’s anemia 2) paroxysmal nocturnal hemoglobinuria 3) myelodysplastic syndromes 4) thymoma 5) eosinophilic faciitis 6) graft versus host disease 7) infections – seronegative hepatitis, EBV, parvovirus-B19, HIV/AIDS 8) drugs – chloramphenical, cimetidine, quinacrine, phenylbutazone, hydantoins, gold
Treatment
1) broad-spectrum antibiotics and blood products to temporize 2) bone marrow transplantation if HLA-identical donor available 3) immunosuppression with anti-lymphocyte globulin and/or antithymocyte globulin and/or cyclosporine 4) androgen therapy has been tried with mixed success
Tips for USMLE
if a 21 year-old woman notices easy bruising and extremely heavy menstrual flow, has low platelets, RBC count, and WBC count, and a bone marrow with almost complete replacement of fat cells, think aplastic anemia
Leave a Reply