What is the definition of splenomegaly (enlargement of the spleen)?

Definition of Splenomegaly

Splenomegaly is defined as a spleen length greater than 13 cm when measured in the coronal plane on imaging studies. 1

Measurement Criteria

• Spleen size should be measured using vertical length measurement in the coronal image or by calculating the length by multiplying the number of spleen slices in transverse CT views by the slice thickness 1
• The Lugano Criteria and RECIL 2017 criteria both establish 13 cm as the threshold for clinically significant splenomegaly 1, 2
• Mild splenomegaly is considered to be a spleen size of 11-13 cm in length 2

Clinical Significance

• Splenomegaly is almost always a sign of a systemic condition and requires further evaluation 3
• An enlarged spleen can cause various symptoms including:
  • Abdominal discomfort or pain 1
  • Early satiety 1
  • Potential hematologic abnormalities due to sequestration 1
  • Hypersplenism, which commonly manifests as thrombocytopenia 4

Common Etiologies

• Liver disease, including cirrhosis and portal hypertension 4, 3
• Hematologic disorders:
  • Myeloproliferative neoplasms (primary myelofibrosis, polycythemia vera, essential thrombocythemia) 1, 5
  • Lymphoproliferative disorders (lymphoma, leukemia) 2, 1
• Infectious causes:
  • In tropical regions, malaria and schistosomiasis are common causes 3
  • Infectious mononucleosis in developed countries 3

Diagnostic Approach

• Confirmation of splenomegaly should be done with abdominal imaging, preferably ultrasonography 3
• Initial laboratory evaluation should include complete blood count, reticulocyte count, and liver function tests 1
• Assessment for signs of systemic illness that commonly cause splenomegaly is necessary 1

Management Considerations

• Treatment should be directed at the underlying cause once diagnosed 2
• For symptomatic splenomegaly in myeloproliferative disorders, JAK inhibitors are recommended as first-line therapy 1
• Splenectomy may be considered for massively enlarged spleens (>20 cm below costal margin) or in patients refractory to medical therapy 1
• Low-dose palliative radiotherapy can provide effective palliation for patients with hematologic disorders and splenomegaly 6

Complications

• Patients with splenomegaly are at risk of:
  • Cytopenias due to splenic sequestration 1
  • Splenic infarction 1
  • Splenic rupture, particularly with contact sports 3
  • Increased bleeding risk due to thrombocytopenia 4