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Last updated: July 12, 2021

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Splenomegaly is enlargement of the spleen. The etiology is diverse and may result from increased splenic activity, decreased venous drainage, or infiltration of the spleen. Symptoms are seldom caused by the size of the spleen directly, but rather due to its hematologic effects on the different cell lines, which manifest as anemia, leucopenia, thrombocytopenia, or as a combination of these (i.e., pancytopenia). Diagnosis can be made by palpation of the spleen in the left upper quadrant, especially on deep inspiration. Imaging studies such as sonography and CT help detect subclinical splenomegaly. Refractory symptoms may necessitate a splenectomy. Vaccination against encapsulated pathogens is essential to reduce the incidence of overwhelming post-splenectomy infection (OPSI).

Overview of causes of splenomegaly [1]
Cause Pathophysiology Associated diseases
Increased splenic activity
  • Increased degradation of defective or structurally abnormal blood cells (work hypertrophy)
Decreased venous drainage
Splenic infiltration
  • Suppression of splenic tissue

Myeloproliferative disorders are commonly accompanied by splenomegaly.

  1. Chapman J, Bhimji SS. Splenomegaly. StatPearls. 2017 .