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 ultrasound
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 when hypersplenism is caused by hemolytic anemias.
Treatment of Hypersplenism
Possibly splenectomy or splenic ablation (radiofrequency, microwave, or thermal)
Vaccination and prophylactic antibiotics for splenectomized patients
Treatment is directed at the underlying disorder.
If hypersplenism is the only serious manifestation of the disorder (eg, Gaucher disease), splenic ablation by splenectomy may be indicated. The indications for splenectomy in hypersplenism are detailed below (see table Indications for Splenectomy in Hypersplenism).
Because the intact spleen protects against serious infections with encapsulated bacteria, splenectomy should be avoided whenever possible. 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 with encapsulated microorganisms and are often given daily prophylactic antibiotics such as penicillin, amoxicillin, or erythromycin, particularly when they have regular contact with children. Patients who develop fever should be carefully evaluated for infection.
Indications for Splenectomy in Hypersplenism
Indication | Examples |
|---|---|
Excessive bleeding | Hypersplenic thrombocytopenia Bleeding esophageal varices requiring concomitant shunt procedure Trauma with ruptured spleen with excessive bleeding |
Hemolytic disorders 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* |
Splenic congestion due to vascular abnormalities | Splenic vein obstruction due to thrombosis, external compression, or stenosis Bleeding esophageal varices associated with excessive increased splenic venous pressure due to portal hypertension or Budd-Chiari syndrome |
* The spleen may be up to 30 times larger than normal. | |
