Download 4-Splenomegaly

Splenomegaly
CLINICAL MANIFESTATIONS.
A soft, thin spleen may be palpable in 15% of neonates, 10% of normal children, and 5% of
adolescents.
In most individuals, the spleen must be 2–3 times its normal size before it is palpable.
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.
DIFFERENTIAL DIAGNOSIS.
Differential Diagnosis of Splenomegaly by Pathophysiology
ANATOMIC LESIONS
Severe hemolytic anemias
Hamartomas
Myeloproliferative diseases: chronic myelogenous
leukemia (CML), juvenile CML, myelofibrosis with
myeloid metaplasia, polycythemia vera
Polysplenia syndrome
Osteopetrosis
Hemangiomas and lymphangiomas
Patients receiving granulocyte and granulocytemacrophage colony-stimulating factors
Cysts, pseudocysts
Hematoma or rupture (traumatic)
HYPERPLASIA CAUSED BY HEMATOLOGIC
DISORDERS
Acute and Chronic Hemolysis
[*]
Hemoglobinopathies (sickle cell disease in infancy
with or without sequestration crisis and sickle
variants, thalassemia major, unstable hemoglobins)
Erythrocyte membrane disorders (hereditary
spherocytosis, elliptocytosis, pyropoikilocytosis)
INFECTIONS[†]
Bacterial
Acute sepsis: Salmonella typhi, Streptococcus
pneumoniae, Haemophilus influenzae type b,
Staphylococcus aureus
Chronic infections: infective endocarditis, chronic
meningococcemia, brucellosis, tularemia, catscratch disease
Immune hemolysis (autoimmune and isoimmune
hemolysis)
Local infections: splenic abscess (S. aureus,
streptococci, less often Salmonella species,
polymicrobial species), pyogenic liver abscess
(anaerobic bacteria, gram-negative enteric bacteria),
cholangitis
Paroxysmal nocturnal hemoglobinuria
Viral[*]
Chronic Iron Deficiency
Acute viral infections, especially in children
Extramedullary hematopoiesis
Congenital cytomegalovirus (CMV), herpes simplex,
Erythrocyte enzyme deficiencies (severe G6PD
deficiency, pyruvate kinase deficiency)
rubella
Mixed connective tissue disease
Hepatitis, A, B, and C;CMV
Systemic vasculitis
Epstein-Barr virus (EBV)
Serum sickness
Viral hemophagocytic syndromes: CMV, EBV, HHV-6
Drug hypersensitivity, especially to phenytoin
Human immunodeficiency virus (HIV)
Graft vs host disease
Spirochetal
Sjögren syndrome
Syphilis, especially congenital syphilis
Cryoglobulinemia
Leptospirosis
Amyloidosis
Rickettsial
Sarcoidosis
Rocky Mountain spotted fever
Large granular lymphocytosis and neutropenia
Q fever
Histiocytosis syndromes
Typhus
Hemophagocytic syndromes (nonviral, familial)
Fungal/Mycobacterial
MALIGNANCIES
Miliary tuberculosis
Primary: leukemia (acute, chronic), lymphoma,
angiosarcoma, Hodgkin disease
Disseminated histoplasmosis
Metastatic
South American blastomycosis
Systemic
patients)
candidiasis
(in
STORAGE DISEASES
immunosuppressed
Parasitic
Lipidosis (Gaucher disease, Niemann-Pick disease,
infantile GM1 gangliosidosis)
Malaria
Mucopolysaccharidoses (Hurler, Hunter-type)
Toxoplasmosis, especially congenital
Mucolipidosis (I-cell disease, sialidosis, multiple
sulfatase deficiency, fucosidosis)
Toxocara canis, Toxocara cati (visceral larva migrans)
Leishmaniasis (kala-azar)
Defects in carbohydrate metabolism: galactosemia,
fructose intolerance
Schistosomiasis (hepatic-portal involvement)
Sea-blue histiocyte syndrome
Trypanosomiasis
Fascioliasis
IMMUNOLOGIC AND INFLAMMATORY
PROCESSES[*]
Systemic lupus erythematosus
Rheumatoid arthritis
CONGESTIVE[*]
Heart failure
Intrahepatic cirrhosis or fibrosis
Extrahepatic portal (thrombosis), splenic, and
hepatic vein obstruction (thrombosis, Budd-Chiari
syndrome)
*
Common.
†
Chronic or recurrent infection suggests underlying immunodeficiency.
Pseudosplenomegaly.
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.
The syndrome of congenital polysplenism includes :
 cardiac defects,
 left-sided organ anomalies,
 bilobed lungs,
 biliary atresia, and
 pseudosplenomegaly
Hypersplenism.
Increased splenic function (sequestration or destruction of circulating cells) results in :
1. peripheral blood cytopenia,
2. increased bone marrow activity, and
3. 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.
Congestive Splenomegaly (Banti Syndrome).
Splenomegaly may result from obstruction in the hepatic, portal, or splenic veins.
Wilson disease , galactosemia , biliary atresia , and α-antitrypsin deficiency may result in
hepatic inflammation, fibrosis, and vascular obstruction.
Congenital abnormalities of the portal (absent or hypoplastic) or splenic veins may cause
vascular obstruction.
Septic omphalitis or thrombophlebitis may be spontaneous or may occur as a result of umbilical
venous catheterization in neonates and may also result in secondary obliteration of these
vessels.
Splenic venous flow may be obstructed by masses of sickled erythrocytes.
When the spleen is the site of vascular obstruction, splenectomy cures hypersplenism.
However, the obstruction usually is in the hepatic or portal systems. In these latter cases,
portocaval shunting may be more helpful, because both portal hypertension and
thrombocytopenia contribute to variceal bleeding.