Aplastic anemia

• • Aplastic Anemia
    • syndrome of chronic primary hematopoietic failure and attendant pancytopenia (anemia, neutropenia, and thrombocytopenia).
    • Persistent marrow aplasia occur most commonly viral hepatitis of the non-A, non-B, non-C, non-G type (MCQ)
    • Fanconi anemia
      • autosomal recessive disorder  (MCQ)

 

• caused by defects in a multiprotein complex that is required for DNA repair  (MCQ)

 

• • • • Marrow hypofunction
      • accompanied by multiple congenital anomalies
        • hypoplasia of the kidney and spleen

 

• Bone anomalies, which most commonly involve the thumbs or radii. (MCQ)

 

• • • Inherited defects in telomerase are found in 5% to 10% of adult-onset aplastic anemia  (MCQ)

 

• about 65% of cases fall into this idiopathic category. (MCQ)

 

• • • Antithymocyte globulin and cyclosporine are used in treatment
    • they suppress or kill autoreactive T-cell clones. (MCQ)
    • Morphology

 

• markedly hypocellular bone marrow is largely devoid of hematopoietic cells;

 

• • • • often only fat cells, fibrous stroma, and scattered lymphocytes and plasma cells remain. (MCQ)
      • Marrow aspirates often yield little material (a “dry tap”);
      • aplasia is best appreciated in marrow biopsies
      • If the anemia necessitates multiple transfusions, systemic hemosiderosis can appear.
      • Splenomegaly is characteristically absent (MCQ)
        • if  splenomegaly is present, the diagnosis of aplastic anemia should be seriously questioned.
      • The red cells are usually slightly macrocytic and normochromic.
      • Reticulocytopenia is the rule. (MCQ)
    • The diagnosis rests on examination of a bone marrow biopsy.
    • other causes of pancytopenia (MCQ)

 

• “aleukemic” leukemia

 

• • • • myelodysplastic syndromes
    • In aplastic anemia, the marrow is hypocellular (and usually markedly so), myeloid neoplasms are associated with hypercellular marrows filled with neoplastic progenitors. (MCQ)
    • Bone marrow transplantation  is treatment of choice in those with a suitable

 

• Pure Red Cell Aplasia

 

• • • a primary marrow disorder
    • only erythroid progenitors are suppressed
    • may occur in association with

 

• thymoma  (MCQ)

 

• • • • large granular lymphocytic leukemia
      • drug exposures
      • autoimmune disorders,

 

• parvovirus infection  (MCQ)

 

• • Myelophthisic anemia
    • a form of marrow failure
    • caused by space-occupying lesions replace normal marrow elements
    • Causes
      • commonest cause is metastatic cancer (MCQ)
        • most often carcinomas arising in the breast, lung, and prostate. (MCQ)
      • any infiltrative process (e.g., granulomatous disease) involving the marrow can produce identical findings.

 

• Leukoerythroblastosis is seen  (MCQ)

 

• • • • abnormal release of nucleated erythroid precursors and immature granulocytic forms (leukoerythroblastosis) into peripheral smears
    • teardrop-shaped red cells is seen (MCQ)

 

• which are believed to be deformed during their tortuous escape from the fibrotic marrow.

 

• • Major Causes of Aplastic Anemia
    • ACQUIRED
      • Idiopathic
        • Acquired stem cell defects
        • Immune mediated
      • Chemical Agents
        • Dose related
          • Alkylating agents (MCQ)
          • Antimetabolites
          • Benzene
          • Chloramphenicol (MCQ)
          • Inorganic arsenicals
        • Idiosyncratic
          • Chloramphenicol (MCQ)
          • Phenylbutazone
          • Organic arsenicals
          • Methylphenylethylhydantoin
          • Carbamazapine (MCQ)
          • Penicillamine
          • Gold salts
      • Physical Agents
        • Whole-body irradiation
      • Viral Infections
        • Hepatitis (unknown virus)
        • Cytomegalovirus infections
        • Epstein-Barr virus infections
        • Herpes zoster (Varicella zoster)
    • INHERITED
      • Fanconi anemia (MCQ)
      • Telomerase defects