USMLE – Splenomegaly
The spleen may be enlarged by involvement by lymphoproliferative disease, by the resumption of extramedullary hemopoiesis in myeloproliferative disease, or by enhanced reticulo-endothelial activity in autoimmune hemolysis. Massive splenomegaly occurs in chronic myeloid leukemia, myelofibrosis, malaria or kala-azar. Hepatosplenomegaly is more suggestive of lympho- or myeloproliferative disease, liver disease and infiltration such as amyloid. The additional presence of lymphadenopathy makes a diagnosis of lymphoproliferative disease more likely. An enlarged spleen may cause abdominal discomfort, with back pain and abdominal bloating due to stomach compression. Splenic infarction may occur and produce severe abdominal pain radiating to the left shoulder tip, associated with a splenic rub on auscultation. Rarely, spontaneous or traumatic rupture may occur.
Investigation will center on the suspected cause. Imaging of the spleen by ultrasound or computed tomography (CT) will detect variations in density in the spleen which may be a feature of lymphoproliferative disease; it also allows visualization of the liver or abdominal lymph nodes. Biopsy of the latter or superficial nodes may provide the diagnosis. A chest radiograph to exclude hilar nodes may be helpful. An FBC may show pancytopenia secondary to hypersplenism and if other abnormalities are present. such as abnormal lymphocytes or a leucoerythroblastic blood film, a bone marrow examination may be helpful. Screening for liver or infectious disease may be appropriate. If all investigations are unhelpful, splenectomy may be diagnostic.