Hypersplenism is cytopenia caused by splenomegaly.
(See also Overview of the Spleen.)
Hypersplenism is a secondary process that can arise from splenomegaly of almost any cause (see table Common Causes of Splenomegaly). Splenomegaly increases the spleen’s mechanical filtering and destruction of red blood cells (RBCs) and often of white blood cells (WBCs) and platelets. Compensatory bone marrow hyperplasia occurs in those cell lines that are reduced in the circulation.
Symptoms and Signs of Hypersplenism
Splenomegaly is the hallmark; spleen size correlates with the degree of cytopenia. Other clinical findings usually result from the underlying disorder.
Diagnosis of Hypersplenism
Physical examination
Sometimes ultrasonography
Complete blood count
Hypersplenism is suspected in patients with splenomegaly and anemia or cytopenias. Evaluation is similar to that of splenomegaly.
Unless other mechanisms coexist to compound their severity, anemia and other cytopenias are modest and asymptomatic (eg, platelet counts, 50 to 100 × 103/mcL [50 to 100 × 109/L]; white blood cell counts, 2500 to 4000/mcL [2.5 to 4 × 109/L] with normal white cell differential count). Red blood cell morphology is generally normal except for teardrop forms and occasional spherocytosis. Reticulocytosis is usual.
Treatment of Hypersplenism
Possibly splenic ablation (splenectomy or radiation therapy)
Vaccination and prophylactic antibiotics for splenectomized patients
Treatment is directed at the underlying disorder. However, if hypersplenism is the only serious manifestation of the disorder (eg, Gaucher disease), splenic ablation by splenectomy or radiation therapy may be indicated. The indications for splenectomy or radiation therapy in hypersplenism are detailed below (see table Indications for Splenectomy or Radiation Therapy in Hypersplenism).
Because the intact spleen protects against serious infections with encapsulated bacteria, splenectomy should be avoided whenever possible, and patients undergoing splenectomy require prior vaccination against infections caused by Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Patients should also receive influenza and COVID-19 vaccines and may need other vaccinations depending on their clinical situation.
After splenectomy, patients are particularly susceptible to severe sepsis
Indications for Splenectomy or Radiation Therapy in Hypersplenism
Indication | Examples |
|---|---|
Excessive bleeding | Hypersplenic thrombocytopenia |
Hemolytic syndromes in which splenomegaly further shortens the survival of intrinsically abnormal red blood cells | |
Mechanical encroachment on other abdominal organs | Calyceal obstruction in left kidney Stomach with early satiety |
Severe pancytopenia associated with massive splenomegaly | Hairy cell leukemia Lipid-storage diseases* |
Vascular insults involving the spleen | Bleeding esophageal varices associated with excessive splenic venous return due to portal hypertension Recurrent infarctions |
* The spleen may be up to 30 times larger than normal. | |
