What are the causes of Splenomegaly (enlarged spleen)?

From the Guidelines

Splenomegaly is most commonly caused by infections, hematologic disorders, liver diseases, autoimmune conditions, and storage disorders, with the specific cause often dictating the approach to management and treatment. The causes of splenomegaly can be broadly categorized into several key areas, including:

• Infections such as bacterial infections (e.g., endocarditis), viral infections (e.g., mononucleosis), and parasitic diseases (e.g., malaria) 1
• Hematologic disorders, including leukemias, lymphomas, hemolytic anemias, and myeloproliferative disorders, which can lead to splenomegaly due to the accumulation of abnormal cells or the spleen's increased workload in filtering these cells 1
• Liver diseases that cause portal hypertension, such as cirrhosis, leading to spleen enlargement due to increased blood flow 1
• Autoimmune conditions like rheumatoid arthritis, systemic lupus erythematosus, and sarcoidosis, which can cause splenomegaly through immune system activation 1
• Storage disorders, including Gaucher disease and Niemann-Pick disease, resulting in spleen enlargement from the accumulation of unmetabolized substances 1
• Congestive heart failure, which may cause passive congestion of the spleen 1
• Splenic cysts, hemangiomas, and metastatic tumors, which can directly increase splenic size 1

Diagnosis of the underlying cause of splenomegaly typically involves a combination of blood tests, imaging studies, and sometimes a spleen biopsy to identify the specific mechanism leading to spleen enlargement 1. Management and treatment strategies vary widely depending on the underlying cause, ranging from medical therapies aimed at reducing spleen size or managing symptoms, to more invasive procedures like splenectomy in certain cases 1. The choice of treatment should prioritize minimizing morbidity, mortality, and improving quality of life, with splenectomy generally reserved for cases where other treatments have failed or are not tolerated 1.

From the Research

Causes of Splenomegaly

• Splenomegaly can be due to several mechanisms, but is almost always a sign of a systemic condition 2
• The most common causes of splenomegaly in the United States are liver disease, malignancy, and infection 2
• Infectious mononucleosis is a common cause of splenomegaly, especially in the athletic population 3
• Malaria and schistosomiasis are common causes of splenomegaly in tropical regions, where as many as 80% of people may have splenomegaly 2
• Other potential causes of splenomegaly include hematologic disorders, such as anemia, and systemic illnesses, such as liver disease 2

Risk Factors for Splenomegaly

• Patient habits, travel, and medical conditions can increase the risk of splenomegaly and suggest etiology 2
• Certain populations, such as college students, are at higher risk for infectious mononucleosis, which can cause splenomegaly 3
• People living in tropical regions are at higher risk for malaria and schistosomiasis, which can cause splenomegaly 2

Diagnosis and Management of Splenomegaly

• Diagnosis of splenomegaly typically involves physical examination and abdominal ultrasonography 2
• Management of splenomegaly involves treating the underlying disease process, and may include splenectomies and spleen reduction therapies 2
• Patients with limited splenic function require increased vaccination and prophylactic antibiotics for procedures involving the respiratory tract 2