Cytology of the spleen

Fine-needle aspiration of the spleen is a safe and useful diagnostic technique, even in animals with thrombocytopenia. Indications for splenic cytology include focal splenic lesions, diffuse splenomegaly, and characterization of hematologic disease. Nonneoplastic disorders of the spleen that may be diagnosed in cytologic specimens include generalized, lymphoid, and histiocytic hyperplasia; extramedullary hematopoiesis; hemosiderosis; and septic and nonseptic inflammation. Splenic aspirates are excellent specimens for the diagnosis and staging of hemolymphatic neoplasia, including lymphoma, mast cell neoplasia, histiocytic neoplasia, plasma cell neoplasia, and leukemia. Mesenchymal (connective tissue) neoplasia, such as hemangiosarcoma and, less often, metastatic carcinoma, also may be diagnosed cytologically. Interpretation of splenic cytology results is enhanced by concurrent evaluation of peripheral blood, bone marrow, and, in some cases, liver and lymph nodes.