Diseases related to the spleen primarily include splenic space-occupying lesions, hematological disorders, infectious diseases, congestive splenomegaly, and splenic injuries.
Primary Splenic Diseases and Space-Occupying Lesions
Wandering Spleen
Also known as ectopic spleen, this condition refers to the spleen being positioned outside its normal anatomical location in the abdominal cavity. It commonly results from congenital elongation or absence of the splenic pedicle and ligaments, allowing the spleen to move downward along the left side of the abdomen to the pelvic cavity. Patients primarily present with a movable abdominal mass and symptoms caused by compression of adjacent organs. Approximately 20% of cases involve splenic torsion, which can cause splenic congestion and acute infarction, presenting as acute severe abdominal pain and sometimes shock. Splenectomy is considered the treatment for wandering spleen.
Splenic Cysts
Splenic cysts are classified as true cysts or pseudocysts. True cysts include dermoid cysts, lymphangiomas, and parasitic cysts, with hydatid cysts being the most common. Pseudocysts are often the result of old hematomas from splenic injury or liquefaction of splenic infarcts. Small cysts are typically asymptomatic, while larger cysts may cause symptoms such as left upper abdominal discomfort and dyspepsia due to mass effect. Small, non-parasitic, and non-neoplastic cysts generally require no treatment. Large cysts may be treated with cystectomy, partial splenectomy, splenectomy, or laparoscopic cyst fenestration and drainage, depending on the circumstances.
Splenic Tumors
Splenic tumors are rare. Benign tumors, such as hemangiomas and hemangioendotheliomas, are often asymptomatic if small, but larger tumors may cause splenomegaly and symptoms associated with compression of adjacent organs. Surgical resection of benign tumors generally has a good outcome. Malignant splenic tumors, such as sarcomas, progress rapidly. In cases with no metastasis, splenectomy combined with radiotherapy or chemotherapy is the preferred treatment. Metastatic tumors in the spleen are uncommon.
Splenic Abscess
Splenic abscesses are often secondary to hematogenous infections and are complications of systemic infectious diseases. They may also result from infection secondary to splenic rupture. Clinical manifestations include chills, fever, left upper abdominal or chest pain, tenderness in the left upper abdomen, and pain on percussion in the splenic area. Ultrasonography and CT imaging assist in diagnosis. Treatment options include antibiotic therapy, ultrasound- or CT-guided aspiration or drainage, and splenectomy.
Other Conditions
Accessory spleens, splenic tuberculosis, and splenic infarctions are other splenic conditions. Splenectomy may be considered when necessary.
Hematological Disorders
Hemolytic Anemia
Hemolytic anemia is often associated with congenital or genetic factors and autoimmune dysfunctions. The spleen contributes to the condition by serving as a site for blood cell destruction or the production of autoantibodies. Congenital forms include hereditary spherocytosis, hereditary elliptocytosis, pyruvate kinase deficiency, sickle cell anemia, and thalassemia. These conditions manifest primarily as anemia, jaundice, and splenomegaly. Splenectomy is the most effective treatment for hereditary spherocytosis. Autoimmune hemolytic anemia involves abnormal destruction of red blood cells due to autoantibody production. It is classified based on serological features into warm antibody type and cold antibody type, with the former being more common. Splenectomy is effective for the warm antibody type.
Thrombocytopenic Purpura
Thrombocytopenic purpura is a bleeding disorder caused by platelet destruction due to autoantibodies. Idiopathic thrombocytopenic purpura is the most common subtype.
Chronic Leukemia
Chronic myeloid leukemia may lead to severe pain in the splenic area due to splenic infarction and perisplenitis, along with significant thrombocytopenia. Enlarged spleens may rupture or become resistant to chemotherapy. Splenectomy can be performed if the overall condition permits. Similar criteria apply to chronic lymphocytic leukemia.
Lymphoma
Lymphoma originates from lymph nodes or other lymphatic tissues and is classified into Hodgkin’s lymphoma (Hodgkin's disease) and non-Hodgkin’s lymphoma. Symptoms include painless lymph node enlargement, often accompanied by splenomegaly. Late-stage presentations include cachexia, fever, and anemia. Advances in non-invasive and minimally invasive diagnostic techniques, such as CT and laparoscopy, along with improved efficacy of radiotherapy and combination chemotherapy, have reduced the need for exploratory laparotomy and splenectomy for staging.
Myelodysplastic Syndrome
Also known as myelofibrosis, this disorder involves diffuse fibrotic proliferation in the bone marrow and extramedullary hematopoiesis in the spleen, liver, and lymph nodes. Symptoms include anemia, splenomegaly, fever, and bone pain. Splenectomy is indicated for severe hemolysis, massive splenomegaly, splenic infarction, or failure to respond to hormonal therapy.
Inherited Metabolic Disorders Related to the Spleen
These include lipid metabolism disorders caused by the accumulation of cerebrosides and sphingomyelin in the monocyte-macrophage system, leading to splenomegaly and hypersplenism. Examples include Gaucher’s disease (glucocerebrosidosis) and Niemann-Pick disease (sphingomyelin lipidosis). Gaucher’s disease is an autosomal recessive disorder caused by β-glucosidase deficiency, resulting in the accumulation of glucocerebrosides in monocytes and macrophages. Splenectomy may be performed in cases of severe hypersplenism, profound thrombocytopenia, or massive splenomegaly affecting cardiopulmonary function.
Infectious Diseases
Acute infectious diseases, such as sepsis, typhoid fever, infectious mononucleosis, and subacute bacterial endocarditis, can cause increased red blood cell destruction within the circulatory system, leading to splenomegaly and hypersplenism. Secondary hypersplenism typically resolves upon control of the underlying condition. Splenectomy is generally not indicated unless complicated by splenic rupture or abscess formation. Chronic infections, such as recurrent malaria and tuberculosis, may result in varying degrees of splenomegaly and hypersplenism, and splenectomy can be considered based on the specific circumstances.
Congestive Splenomegaly
Congestive splenomegaly and hypersplenism caused by portal hypertension due to liver cirrhosis are indications for splenectomy, with alcohol-related liver cirrhosis being a common cause.