section name header

Info


A. Functions

  1. Filtration of Blood
    1. Removal of infectious agents
    2. Removal of "old" cells - mainly old erythrocytes and platelets
    3. Removal of condensed nuclear material from erythrocytes
  2. Immune responses
    1. Especially against encapsulated organisms
    2. Including: H. influenza, S. pneumoniae, N. meningitides
  3. Normal size ~12cm long x 7cm wide x ~5cm deep
  4. Evaluation of Spleen Size
    1. Physical exam for splenomegaly is not specific, sensitive, and is highly variable
    2. Radiographic study is required to evaluate spleen size accurately
    3. Abdominal ultrasound and/or computerized tomographic scan should be used

B. Differential of Splenomegaly [1]

  1. Infections
    1. Infectious mononucleosis (Epstein-Barr Virus)
    2. Bacterermia / Bacterial Endocarditis
    3. Tuberculosis
    4. Malaria
    5. HIV Disease
    6. Viral Hepatitis
    7. Other: histoplasmosis, leishmaniasis, trypanosoma
  2. Infiltrative Diseases
    1. Benign - amyloidosis, Gaucher's disease, other glycogen storage disease, hematopoiesis
    2. B lymphoproliferative disorder, nonspecific
    3. Myeloproliferative syndromes
    4. Lymphomas: Hodgkin's, Non-Hodgkin's (tropical splenic lymphoma, other)
    5. Leukemias, particularly chronic myelogenous leukemia (CML)
  3. Abnormal Immune System
    1. Felty's Syndrome - Rheumatoid Arthritis with splenomegaly and neutropenia
    2. Systemic Lupus Erythemaosus (SLE)
    3. Immune Hemolytic Anemias
    4. Angioimmunoblastic lymphadenopathy
    5. Drug reactions with serum sickness
    6. Immune thrombocytopenia and neutropenia
    7. Sarcoidosis
  4. Abnormal Erythrocytes
    1. Sickle cell disease - early stages
    2. Spherocytosis, Elliptocytosis (Ovalocytosis)
    3. Thalassemia
  5. Abnormal Splenic Blood Flow (portal pressures)
    1. Cirrhosis of any cause
    2. Hepatic Vein or Inferior Vena Cava Obstruction
    3. Portal Vein Obstruction
    4. Congestive heart failure (CHF), chronic
    5. Splenic Vein occlusion
    6. Splenic Artery aneurysm
    7. Severe Liver Disease

C. Splenectomy

  1. Trauma is most common indication
  2. Autoimmune Thrombocytopenia
    1. Usually 3rd line therapy
    2. May completely cure problem
    3. ~20% of patients do not respond completely
  3. Anemia
    1. Hereditary Spherocytosis and Elliptocytosis
    2. Thalassemia
    3. Sickle Cell Anemia - patients usually "autosplenectomize" due to microinfarctions
    4. Autoimmune hemolytic Anemia
    5. Pyruvate Kinase Deficiency
  4. Leukemic infiltration
    1. Therapeutic - spleen pressure on intestine, kidney
    2. Diagnostic - Hodgkin's Disease (early stages considering radiation alone)
  5. Felty's Syndrome - with neutropenia
  6. Howell-Jolly Bodies
    1. Reticulocyte chromatin condenses to form Howell-Jolly Bodies
    2. These are usually removed from mature erythrocytes by the spleen
    3. Persons with splenectomy will have Howell-Jolly Bodies
  7. Infectious prophylaxis following splenectomy
    1. Essential due to high risk of sepsis from encapsulated organisms
    2. Vaccinations for pneumococcus, N. meningitides, and H. influenza type B (HIB) required
    3. Multiple vaccinations may be required
    4. Patients should also be vaccinated for influenza q year
    5. Most vaccines are effective in splenectomized (Hodgkin's Disease) patients [2]
  8. Risk of Infection
    1. 3-5% of patients develop an infection within 1 year
    2. Fatal infection occurs in ~2-3% within 3 years of splenectomy
    3. Fever in patients with splenectomy requires urgent evaluation
    4. Increased risk for infection, sepsis, and death
  9. Pathogens Associated with Infection in Splenectomy Patients [3]
    1. Encapsulated organisms
    2. Streptococcus pneumoniae
    3. Haemophilus influenzae
    4. Neisseria meningitidis
    5. Capnocytophaga canimorsus (DF2)

D. Splenosis [4]

  1. Spleen cells can adhere to peritoneum and grow
  2. This can lead to growth of implants which are limited only by other organs
  3. These implants can grow to large sizes, usually as multiple masses
  4. Occurs in ~67% of patients with splenic rupture from trauma
  5. Benign condition in most patients (may have some mass effects)

References

  1. Bedu-Addo G and Bates I. 2002. Lancet. 360(9331):449 abstract
  2. Moltrine DC, George S, Tarbell N, et al. 1995. Ann Intern Med. 123(11):828
  3. Pizzo PA. 1999. NEJM. 341(12):893 abstract
  4. Schenkein DP and Ahmed E. 1995. NEJM. 333(12):784