(See also Overview of the Spleen Overview of the Spleen By structure and function, the spleen is essentially 2 organs: The white pulp, consisting of periarterial lymphatic sheaths and germinal centers, acts as an immune organ. The red pulp, consisting... read more .)
Hypersplenism is a secondary process that can arise from splenomegaly Splenomegaly Splenomegaly is abnormal enlargement of the spleen. (See also Overview of the Spleen.) Splenomegaly is almost always secondary to other disorders. Causes of splenomegaly are myriad, as are the... read more of almost any cause (see table Common Causes of Splenomegaly 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 Splenomegaly Splenomegaly is abnormal enlargement of the spleen. (See also Overview of the Spleen.) Splenomegaly is almost always secondary to other disorders. Causes of splenomegaly are myriad, as are the... read more .
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 Gaucher Disease Gaucher disease is a sphingolipidosis, an inherited disorder of metabolism, resulting from glucocerebrosidase deficiency, causing deposition of glucocerebroside and related compounds. Symptoms... read more ), 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 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 Overview of Immunization Immunity can be achieved Actively by using antigens (eg, vaccines, toxoids) Passively by using antibodies (eg, immune globulins, antitoxins) A toxoid is a bacterial toxin that has been modified... read more against infections caused by Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Patients should also receive the influenza vaccine and may need other vaccinations according to their clinical situation.
After splenectomy, patients are particularly susceptible to severe sepsis Sepsis and Septic Shock Sepsis is a clinical syndrome of life-threatening organ dysfunction caused by a dysregulated response to infection. In septic shock, there is critical reduction in tissue perfusion; acute failure... read more 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 receive empiric antibiotics because rapidly fatal sepsis can sometimes occur.
Indications for Splenectomy or Radiation Therapy in Hypersplenism
Hemolytic syndromes in which splenomegaly further shortens the survival of intrinsically abnormal red blood cells
Hereditary spherocytosis Hereditary Spherocytosis and Hereditary Elliptocytosis Hereditary spherocytosis and hereditary elliptocytosis are congenital red blood cell (RBC) membrane disorders that can cause a mild hemolytic anemia. Symptoms, generally milder in hereditary... read more
Mechanical encroachment on other abdominal organs
Calyceal obstruction in left kidney
Stomach with early satiety
Severe pancytopenia associated with massive splenomegaly
Hairy cell leukemia
Vascular insults affecting the spleen
Bleeding esophageal varices associated with excessive splenic venous return due to portal hypertension
* The spleen may be up to 30 times larger than normal.