If confirmation of splenomegaly is necessary because the examination is equivocal, ultrasonography is the test of choice because of its accuracy and low cost. CT and MRI may provide more detail of the organ’s consistency. MRI is especially useful in detecting portal or splenic vein thromboses. Nuclear scanning is accurate and can identify accessory splenic tissue but is expensive and cumbersome.
Specific causes suggested clinically should be confirmed by appropriate testing. If no cause is suggested, the highest priority is exclusion of occult infection, because early treatment affects the outcome of infection more than it does most other causes of splenomegaly. Testing should be thorough in areas of high geographic prevalence of infection or if the patient appears to be ill. CBC, blood cultures, and bone marrow examination and culture should be considered. If the patient is not ill, has no symptoms besides those due to splenomegaly, and has no risk factors for infection, the extent of testing is controversial but probably includes CBC, peripheral blood smear, liver function tests, and abdominal CT. Flow cytometry and immunochemical assays such as light chain measurements of peripheral blood and/or bone marrow sections is indicated if lymphoma is suspected.
Specific peripheral blood findings may suggest underlying disorders (eg, small-cell lymphocytosis in Chronic Lymphocytic Leukemia (CLL), large granular lymphocytosis in T-cell granular lymphocyte [TGL] hyperplasia or TGL leukemia, atypical lymphocytes in hairy cell leukemia, and leukocytosis and immature forms in other leukemias). Excessive basophils, eosinophils, or nucleated or teardrop RBCs suggest myeloproliferative disorders. Cytopenias suggest Hypersplenism. Spherocytosis suggests hypersplenism or Hereditary Spherocytosis and Hereditary Elliptocytosis. Liver function test results are diffusely abnormal in congestive splenomegaly with cirrhosis; an isolated elevation of serum alkaline phosphatase suggests hepatic infiltration, as in myeloproliferative and lymphoproliferative disorders, Miliary TB, and chronic fungal diseases (eg, Candidiasis (Invasive), Histoplasmosis).
Some other tests may be useful, even in asymptomatic patients. Serum protein electrophoresis identifying a monoclonal gammopathy or decreased immunoglobulins suggests lymphoproliferative disorders or Amyloidosis; diffuse hypergammaglobulinemia suggests chronic infection (eg, Malaria, Leishmaniasis, Brucellosis, Tuberculosis (TB)) or cirrhosis with congestive splenomegaly, Sarcoidosis, or connective tissue disorders. Elevation of serum uric acid suggests a myeloproliferative or lymphoproliferative disorder. Elevation of WBC alkaline phosphatase suggests a myeloproliferative disorder, whereas decreased levels suggest chronic myelocytic leukemia.
If testing reveals no abnormalities other than splenomegaly, the patient should be reevaluated at intervals of 6 to 12 mo or when new symptoms develop.