KEY FACTS
Imaging
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No universal consensus on splenomegaly (SMG) cut off due to variability in normal adult spleen size
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SMG is diagnosed when length > 13 cm; additional measurements of thickness > 5 cm or width > 8 cm may also be used
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Splenic index (product of length, thickness, and width): Normally 120-480 cm³; SMG considered index > 500 cm³
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Color Doppler
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Portal hypertension: Dilated splenic vein (SV); direction of flow may be reversed; SV thrombus, splenic hilar collaterals, splenorenal shunt, recanalized umbilical vein
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SMG with normal echogenicity
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Infection (mononucleosis, Salmonella typhi ), congestion (portal hypertension), early sickle cell disease
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Hereditary spherocytosis, hemolysis, Felty syndrome
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Wilson disease, polycythemia, myelofibrosis, leukemia
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SMG with hyperechoic pattern
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Leukemia, lymphoma, sarcoidosis, metastasis
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Infections (malaria, tuberculosis, brucellosis), hematoma
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Hereditary spherocytosis, polycythemia, myelofibrosis
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SMG with hypoechoic pattern
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Leukemia, lymphoma, sarcoidosis, metastasis
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Infections (malaria, tuberculosis, brucellosis), hematoma
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Hereditary spherocytosis, polycythemia, myelofibrosis
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SMG with mixed echogenic pattern
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Abscesses, metastases, infarction, hemorrhage/hematoma in different stages of evolution, primary malignancy (e.g., lymphoma, angiosarcoma)
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Top Differential Diagnoses
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Splenomegaly without focal mass
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Portal hypertension (cirrhosis)
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Infection (mononucleosis, S. typhi )
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Lymphoma (Hodgkin or non-Hodgkin lymphoma)
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Leukemia and myeloproliferative disorders
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Hematologic disorders (hemoglobinopathy, thrombotic thrombocytopenic purpura)
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Storage diseases (Gaucher, hemosiderosis)
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Solitary splenic masses
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Large splenic abscess
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Hemangioma
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Lymphangioma
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Primary malignancy (e.g., lymphoma, angiosarcoma)
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Metastasis
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Pathology
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Myriad etiologies of SMG; systemic vs. primary splenic, focal lesion(s) vs. diffuse enlargement
Diagnostic Checklist
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Is SMG present by size measurements
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Is SMG diffuse or related to space-occupying lesions
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Any other clues to underlying cause
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SMG usually manifestation of systemic disease, rather than primary splenic pathology
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US best initial test; very useful for estimating spleen size; can distinguish between diffuse SMG or focal abnormality, can assess SV patency and flow direction
Scanning Tips
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Splenic size correlates with height and can exceed normal size in tall, healthy people
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If spleen extends below normal left kidney, highly suggestive of SMG
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Spleen thickness should be measured from hilum to outer convex surface of spleen
