Causes and Clinical Patterns of Splenomegaly

Hepatic Diseases

• The American Association for the Study of Liver Diseases notes that cirrhosis with portal hypertension is a common cause of splenomegaly 1
• Wilson's disease may present with isolated splenomegaly due to clinically inapparent cirrhosis, as reported by the European Association for the Study of the Liver 2
• Non-cirrhotic portal hypertension can cause significant splenomegaly, according to the European Association for the Study of the Liver 3
• The presence of esophageal varices is often associated with splenomegaly and portal hypertension, as noted by the European Association for the Study of the Liver 3
• Ascites is a common complication of splenomegaly with portal hypertension, as reported by the European Association for the Study of the Liver 3

Infectious Diseases

• The Infectious Diseases Society of America notes that parasitic infections, such as malaria and schistosomiasis, are common causes of splenomegaly in tropical regions 4
• Autoimmune disorders, including rheumatoid arthritis with Felty syndrome, can cause splenomegaly, as reported by the Infectious Diseases Society of America 4

Lysosomal Storage Disorders

• The American College of Medical Genetics and Genomics recommends genetic testing for acid sphingomyelinase deficiency (ASMD/Niemann-Pick disease) in patients with unexplained hepatosplenomegaly 5
• Gaucher disease is a common cause of significant splenomegaly, as noted by the American College of Medical Genetics and Genomics 5
• Niemann-Pick disease type C and lysosomal acid lipase deficiency (LALD) are also associated with splenomegaly, as reported by the American College of Medical Genetics and Genomics 5

Clinical Patterns and Associations

• The American Association for the Study of Liver Diseases notes that splenomegaly with portal hypertension is often associated with thrombocytopenia 6
• Decreased portal blood flow velocity on Doppler ultrasound is a common finding in patients with splenomegaly and portal hypertension, as reported by the American Association for the Study of Liver Diseases 6
• The American Association for the Study of Liver Diseases recommends assessing for cytopenias, including thrombocytopenia, in patients with splenomegaly 7
• Hypersplenism, which can occur in many conditions causing splenomegaly, is often associated with cytopenias, as noted by the American Association for the Study of Liver Diseases 7

Diagnostic Approach

• The American College of Medical Genetics and Genomics recommends complete blood count, liver function tests, and abdominal ultrasound as initial evaluation for splenomegaly 8
• Lipid profile may reveal mixed dyslipidemia in storage disorders, as reported by the American College of Medical Genetics and Genomics 8
• Genetic testing, such as SMPD1 gene for ASMD, is recommended for suspected storage disorders, as noted by the American College of Medical Genetics and Genomics 8

Splenomegaly Causes and Associations

Infectious Causes

• Malaria and schistosomiasis are common causes of splenomegaly in tropical regions, according to the Journal of Travel Medicine 9

Autoimmune and Inflammatory Disorders

• Systemic lupus erythematosus (SLE) may present with splenomegaly, as reported in Blood 10

Diagnostic Approach

• Bone marrow examination may be informative in patients older than 60 years or those with systemic symptoms, as suggested in Blood 10
• In patients with suspected ITP, mild splenomegaly may be found in younger patients, but moderate or massive splenomegaly suggests an alternative cause, according to Blood 10

Diagnostic Approach to Splenomegaly

Hematologic Causes

• The American Society of Hematology recommends that polycythemia vera and essential thrombocythemia be considered as causes of splenomegaly, with progression to post-PV or post-ET myelofibrosis defined by increasing splenomegaly ≥5 cm from left costal margin 11
• The American Society of Hematology suggests that hairy cell leukemia characteristically presents with splenomegaly; resolution of palpable splenomegaly is required for complete remission, and flow cytometry for lymphoproliferative disorders (CD19, CD20, CD11c, CD25, CD103, CD123, CD200 for hairy cell leukemia) is recommended 12

Diagnostic Evaluation

• The American College of Radiology recommends that abdominal ultrasound be used to confirm splenomegaly, measure spleen size, assess for portal hypertension signs, and evaluate liver parenchyma, and peripheral blood smear to identify abnormal cells, hairy cells, or leukoerythroblastic picture 11, 12
• The American Society of Clinical Oncology suggests that JAK2V617F, MPL, and CALR mutation testing for myeloproliferative neoplasms be considered in patients with suspected hematologic disease 11

Massive Splenomegaly Causes and Characteristics

Hematologic/Myeloproliferative Disorders

• Chronic myelomonocytic leukemia (CMML) frequently presents with splenomegaly, though often limited; however, some patients develop massive splenomegaly requiring intervention 13, 14

Hepatic Diseases with Portal Hypertension

• Cirrhosis with portal hypertension from any cause commonly causes splenomegaly, and idiopathic non-cirrhotic portal hypertension (INCPH) causes significant splenomegaly more commonly than other causes of portal hypertension 15
• INCPH patients often have low liver stiffness (<12 kPa) on transient elastography, helping distinguish from cirrhosis, and are often radiologically misclassified as cirrhotic on ultrasound due to liver surface nodularity and portal vein wall thickening 15

Splenomegaly Diagnosis and Measurement

Definition and Imaging

• The American College of Radiology recommends measuring the vertical length of the spleen on coronal imaging, typically greater than 13 cm, to define splenomegaly 16
• The American College of Radiology suggests measuring the vertical length on coronal CT images or calculating it by multiplying the number of spleen slices in transverse CT views by slice thickness 16
• The American Association for the Study of Liver Diseases recommends abdominal ultrasound as the first-line imaging modality to confirm splenomegaly and measure spleen size 17

Diagnostic Approach

• The American Association for the Study of Liver Diseases recommends liver function tests, including total bilirubin, AST, ALT, alkaline phosphatase, and GGT, to be performed annually 17
• The American Association for the Study of Liver Diseases suggests using fibrosis indices, such as APRI, to detect advanced fibrosis and portal hypertension 17

Splenomegaly Classification and Characteristics

Etiologic Classification

• Gaucher disease is the most common lysosomal storage disorder causing significant splenomegaly, with 90% of type 1 patients affected, according to the American College of Medical Genetics and Genomics 18
• Glycogen storage diseases frequently present with hepatomegaly, with some types also causing splenomegaly, as reported by the American College of Medical Genetics and Genomics 19

Clinical Pattern Recognition

• Mild splenomegaly in idiopathic thrombocytopenic purpura (ITP) occurs in less than 3% of patients; moderate or massive splenomegaly suggests an alternative diagnosis, as stated by the American Society of Hematology 20
• The presence of splenomegaly greater than 3% palpability in adults essentially excludes ITP as a diagnosis, according to the American Society of Hematology 20

Differential Diagnosis of Splenomegaly

Primary Diagnostic Categories

• Chronic myeloid leukemia (CML) presents with splenomegaly as a defining feature, measured as distance below costal margin, according to the American Society of Clinical Oncology 21

Infectious Diseases

• Visceral leishmaniasis (kala-azar) presents with chronic fever, weight loss, splenomegaly, pancytopenia, hypoalbuminemia, and elevated inflammatory markers, as reported by the Infectious Diseases Society of America 22
• Rheumatoid arthritis with Felty syndrome causes splenomegaly, as noted by the American College of Rheumatology 22

Infiltrative/Storage Disorders

• Massive splenomegaly with hepatomegaly in storage disorders helps differentiate from glycogen storage diseases, which rarely cause significant splenomegaly, according to the American College of Medical Genetics and Genomics 23

Splenic Complications in Sickle Cell Disease

Chronic Splenomegaly and Indications for Splenectomy

• In individuals with sickle cell disease, persistent enlargement of the spleen can occur and may necessitate surgical removal of the organ (splenectomy) to manage complications. 24

Acute Splenic Sequestration Presentation

• Sickle cell disease can present acutely with splenic sequestration, characterized by sudden pallor and the risk of severe anemia due to rapid pooling of blood in the spleen. 24