The spleen is best examined in a supine patient by palpating across the abdomen toward the left costal margin from below as the patient inspires deeply. An enlarged spleen might descend into the pelvis; when splenomegaly is suspected, the abdominal examination should begin at a lower starting point. Superficial abdominal venous distention may be present when splenomegaly is a result of portal hypertension.
Radiologic detection or confirmation of splenic enlargement is done with ultrasonography, CT, or technetium-99 sulfur colloid scan. The latter also assesses splenic function.
Abnormally enlarged mesenteric connections may produce a wandering or ptotic spleen. An enlarged left lobe of the liver, a left upper quadrant mass, or a splenic hematoma may be mistaken for splenomegaly. Splenic cysts may contribute to splenomegaly or mimic it; these may be congenital (epidermoid) or acquired (pseudocyst) after trauma or infarction. Cysts are usually asymptomatic and are found on radiologic evaluation. Splenosis after splenic rupture or an accessory spleen (present in 10% of normal individuals) may also mimic splenomegaly; most are not palpable.
Increased splenic function (sequestration or destruction of circulating cells) results in peripheral blood cytopenia, increased bone marrow activity, and splenomegaly. It is usually secondary to another disease and may be cured by treatment of the underlying condition or, if absolutely necessary, moderated by splenectomy.