Chapter 26: Hypersplenism and Hyposplenism

THE SPLEEN

The white pulp (lymphoid tissue) functions in antigen processing and antibody production.
The red pulp (monocyte-macrophage system) serves as a filter, retaining defective blood cells and foreign particles.

HYPERSPLENISM (INCREASED SPLENIC FUNCTION)

Hypersplenism is considered “appropriate” if it is an exaggeration of normal function, as in hereditary spherocytosis or idiopathic thrombocytopenic purpura, or “inappropriate” if the hyperfunction is a result of vascular congestion or infiltrative disease.
It is usually associated with splenomegaly.
It causes cytopenias with associated compensatory bone marrow hyperplasia.
It usually is corrected by splenectomy, if indicated.
Table 26–1 lists the causes of hypersplenism. Table 26–2 lists the causes of massive splenomegaly.

TABLE 26–1CLASSIFICATION AND THE MOST COMMON CAUSES OF SPLENOMEGALY AND HYPERSPLENISM

View Table|Favorite Table|Download (.pdf)

TABLE 26–1 CLASSIFICATION AND THE MOST COMMON CAUSES OF SPLENOMEGALY AND HYPERSPLENISM

Congestive
1. Right-sided congestive heart failure
2. Budd-Chiari syndrome (hepatic vein thrombosis with or without inferior vena cava extension)
3. Cirrhosis with portal hypertension
4. Portal or splenic vein thrombosis
Immunologic
1. Viral infection
  1. Acute HIV infection/chronic infection
  2. Acute mononucleosis
  3. Dengue fever
  4. Rubella (rare except newborns)
  5. Cytomegalovirus infection (rare except newborns)
  6. Herpes simplex (rare except newborns)
2. Bacterial infection
  1. Subacute bacterial endocarditis
  2. Brucellosis
  3. Tularemia
  4. Melioidosis
  5. Listeriosis
  6. Plague
  7. Secondary syphilis
  8. Relapsing fever
  9. Psittacosis
  10. Anaplasmosis (formerly ehrlichiosis)
  11. Rickettsial diseases (scrub typhus, Rocky Mountain spotted fever, Q fever)
  12. Tuberculosis
  13. Splenic abscess (most common organisms are Enterobacteriaceae, Staphylococcus aureus, streptococcus group D, and anaerobic organisms as part of mixed flora infections)
3. Fungal Infection
  1. Blastomycosis
  2. Histoplasmosis
  3. Systemic candidiasis and hepatosplenic candidiasis
4. Parasitic infection
  1. Malaria
  2. Kala-azar
  3. Leishmaniasis
  4. Schistosomiasis
  5. Babesiosis
  6. Coccidioidomycosis
  7. Paracoccidioidomycosis
  8. Trypanosomiasis (cruzi, brucei)
  9. Toxoplasmosis (rare except newborns)
  10. Echinococcosis
  11. Cysticercosis
  12. Visceral larva migrans (Toxocara infection)
5. Inflammatory/autoimmune
  1. Systemic lupus erythematosus (SLE)
  2. Felty syndrome
  3. Juvenile rheumatoid arthritis
  4. Autoimmune lymphoproliferative syndrome (ALP syndrome)
  5. Hemophagocytic syndrome
  6. Common variable immunodeficiency
  7. Anti-D immunoglobulin administration
Associated with hemolysis
1. Thalassemia major and intermedia
2. Pyruvate kinase deficiency
3. Hereditary spherocytosis
4. Autoimmune hemolytic anemia (rare)
5. Sickle cell disease, more common in early childhood (splenic sequestration), hemoglobin C disease, and some other hemoglobinopathies
Infiltrative
1. Nonmalignant
  1. Splenic hematoma (splenic cysts are usually a late complication of a hematoma)
  2. Littoral cell angioma
  3. Disorders of sphingolipid metabolism
    1. Gaucher disease
    2. Niemann-Pick disease
  4. Cystinosis
  5. Amyloidosis (light-chain amyloid and amyloid A protein)
  6. Multicentric Castleman disease
  7. Mastocytosis
  8. Hypereosinophilic syndrome
  9. Sarcoidosis
2. Extramedullary hematopoiesis
  1. Primary myelofibrosis
  2. Osteopetrosis (childhood)
  3. Thalassemia major
3. Malignant
  1. Hematologic
    1. Chronic lymphocytic leukemia (especially prolymphocytic variant)
    2. Chronic myeloid leukemia
    3. Polycythemia vera
    4. Hairy cell leukemia
    5. Heavy chain disease
    6. Hepatosplenic lymphoma
    7. Acute leukemia (acute lymphoblastic leukemia/acute myeloid leukemia)
    8. Hodgkin and other lymphomas
  2. Nonhematologic
    1. Metastatic carcinoma (rare)
    2. Neuroblastoma
    3. Wilms tumor
    4. Leiomyosarcoma
    5. Fibrosarcoma
    6. Malignant fibrous histiocytoma
    7. Kaposi sarcoma
    8. Hemangiosarcoma
    9. Lymphangiosarcoma
    10. Hemangioendothelial sarcoma
Iatrogenic
1. Granulocyte colony-stimulating factor administration
2. Erythropoietin administration