Chapter 060. Enlargement of Lymph Nodes and Spleen (Part 6)

The differential diagnostic possibilities are much fewer when the spleen is "massively enlarged," palpable more than 8 cm below the left costal margin or its drained weight is ≥1000 g (Table 60-3). The vast majority of such patients will have non-Hodgkins lymphoma, chronic lymphocytic leukemia, hairy cell leukemia, chronic myelogenous leukemia, myelofibrosis with myeloid metaplasia, or polycythemia vera. Table 60-3 Diseases Associated with Massive SplenomegalyaChronic myelogenous leukemiaGauchers diseaseLymphomasChroniclymphocyticleukemiaHairy cell leukemiaSarcoidosisMyelofibrosis metaplasiawithmyeloidAutoimmune anemiahemolyticPolycythemia veraDiffuse hemangiomatosissplenicaThe spleen extends greater than 8 cm below left costal margin and/or ...
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Chapter 060. Enlargement of Lymph Nodes and Spleen (Part 6) Chapter 060. Enlargement of Lymph Nodes and Spleen (Part 6) The differential diagnostic possibilities are much fewer when the spleen ismassively enlarged, palpable more than 8 cm below the left costal margin or itsdrained weight is ≥1000 g (Table 60-3). The vast majority of such patients willhave non-Hodgkins lymphoma, chronic lymphocytic leukemia, hairy cellleukemia, chronic myelogenous leukemia, myelofibrosis with myeloid metaplasia,or polycythemia vera. Table 60-3 Diseases Associated with Massive Splenomegalya Chronic myelogenous leukemia Gauchers disease Lymphomas Chronic lymphocytic leukemia Hairy cell leukemia Sarcoidosis Myelofibrosis with myeloid Autoimmune hemolyticmetaplasia anemia Polycythemia vera Diffuse splenic hemangiomatosis a The spleen extends greater than 8 cm below left costal margin and/orweighs more than 1000 g Laboratory Assessment The major laboratory abnormalities accompanying splenomegaly aredetermined by the underlying systemic illness. Erythrocyte counts may be normal,decreased (thalassemia major syndromes, SLE, cirrhosis with portal hypertension),or increased (polycythemia vera). Granulocyte counts may be normal, decreased(Feltys syndrome, congestive splenomegaly, leukemias), or increased (infectionsor inflammatory disease, myeloproliferative disorders). Similarly, the plateletcount may be normal, decreased when there is enhanced sequestration ordestruction of platelets in an enlarged spleen (congestive splenomegaly, Gauchersdisease, immune thrombocytopenia), or increased in the myeloproliferativedisorders such as polycythemia vera. The CBC may reveal cytopenia of one or more blood cell types, whichshould suggest hypersplenism. This condition is characterized by splenomegaly,cytopenia(s), normal or hyperplastic bone marrow, and a response to splenectomy.The latter characteristic is less precise because reversal of cytopenia, particularlygranulocytopenia, is sometimes not sustained after splenectomy. The cytopeniasresult from increased destruction of the cellular elements secondary to reducedflow of blood through enlarged and congested cords (congestive splenomegaly) orto immune-mediated mechanisms. In hypersplenism, various cell types usuallyhave normal morphology on the peripheral blood smear, although the red cellsmay be spherocytic due to loss of surface area during their longer transit throughthe enlarged spleen. The increased marrow production of red cells should bereflected as an increased reticulocyte production index, although the value may beless than expected due to increased sequestration of reticulocytes in the spleen. The need for additional laboratory studies is dictated by the differentialdiagnosis of the underlying illness of which splenomegaly is a manifestation. Splenectomy Splenectomy is infrequently performed for diagnostic purposes, especiallyin the absence of clinical illness or other diagnostic tests that suggest underlyingdisease. More often splenectomy is performed for symptom control in patientswith massive splenomegaly, for disease control in patients with traumatic splenicrupture, or for correction of cytopenias in patients with hypersplenism or immune-mediated destruction of one or more cellular blood elements. Splenectomy isnecessary for staging of patients with Hodgkins disease only in those with clinicalstage I or II disease in whom radiation therapy alone is contemplated as thetreatment. Noninvasive staging of the spleen in Hodgkins disease is not asufficiently reliable basis for treatment decisions because one-third of normal-sized spleens will be involved with Hodgkins disease and one-third of enlargedspleens will be tumor-free. Although splenectomy in chronic myelogenousleukemia does not affect the natural history of disease, removal of the massivespleen usually makes patients significantly more comfortable and simplifies theirmanagement by significantly reducing transfusion requirements. Splenectomy isan effective secondary or tertiary treatment for two chronic B cell leukemias, hairycell leukemia and prolymphocytic leukemia, and for the very rare splenic mantlecell or marginal zone lymphoma. Splenectomy in these diseases may be associatedwith significant tumor regression in bone marrow and other sites of disease.Similar regressions of systemic disease have been noted after splenic irradiation insome types of lympho ...