Her physical examination is unremarkable, with the exception of her grade 2/6 systolic ejection murmurs at the upper right sternal border and an enlarged spleen, which spans 10 cm below her left costal margin. Her liver span is normal. Looking for an infectious, hepatic, or cardiac cause of her dizziness, you promptly order some screening laboratory tests and imaging studies.
Her leukocyte count was 2,300/[mm.sup.3] with 64% segmented neutrophils and 26% lymphocytes; hemoglobin was 12.8 g/dL; and platelet count was 49,000/mL. Her Monospot was negative; sedimentation rate was 2 mm/hr; AST was 25 IU/L; ALT was 8 IU/L; bilirubin was 0.8 mg/dL, with a conjugated fraction of 0.2 mg/dL; and ProTime was 14.7 seconds.
Her chest radiograph suggested slight cardiac enlargement but is otherwise clear. How would you proceed with this case?
A 12-year-old girl who is Tanner stage 2 presents with complaints of mild dizzy spells, lasting a few minutes; these have been occurring daily over the last month. She denies any other complaints such as syncope, postural hypotension, or dyspnea.
Her physical examination is unremarkable, with the exception of her grade 2/6 systolic ejection murmurs at the upper right sternal border and an enlarged spleen, which spans 10 cm below her left costal margin. (See p. 2 for a more complete history on this patient.)
SHORT DIFFERENTIAL DIAGNOSIS:
You ponder the causes of massive splenomegaly with normal hepatic function tests, which could include:
* Streptococcal pharyngitis, the most common cause of splenomegaly.
* Congestive heart failure with worsening of her aortic stenosis.
* Viral infections.
WORK-UP: You are concerned about her thrombocytopenia and mild leukopenia, which could be due to a neoplastic process. You order additional blood and imaging studies.
You start by examining potential hepatic causes of splenomegaly. Further testing reveals a negative hepatitis B surface antigen (HbsAg), anti-hepatitis C polymerase chain reaction antibody along with normal ceruloplasmin (for Wilson's disease), [a.sub.1]-antitrypsin (looking for a deficiency), and ferritin and iron levels (for hemochromatosis).
Her abdominal ultrasound reveals a thickened gallbladder and a spleen spanning 18 cm. Abnormal branching of the hepatic vessels within the porta hepatis is present, suggesting portal hypertension, possibly due to cavernous transformation of the portal vein with numerous collateral vessels at the hilum. CT scan confirms these findings (see x-ray below), but no obvious esophageal varices are present.
The enlargement of the inferior vena cava suggests collateral circulation may be compensating for the obstruction. Endoscopy by the gastroenterologist reveals minimal esophageal varices. Her hematologic abnormalities are a consequence of splenic sequestration and not neoplasm.
FINAL DIAGNOSIS: Portal hypertension due to cavernous transformation of the portal vein with numerous collateral vessels at the hilum.
Collateral circulation compensating for the obstruction causes enlargement of the inferior vena cava. The hematologic abnormalities are due to splenic sequestration.
As described in the third edition of "Pediatric Clinical Gastroenterology" by Silverman and Roy (St. Louis: Mosby, 1983), three anatomic levels of portal venous obstruction are recognized: prehepatic structural abnormality of the extrahepatic portal vein (congenital or acquired); intrahepatic diseases of the liver parenchyma, with or without cirrhosis; and suprahepatic obstruction to venous flow outside the liver. Few cases are discovered before 1 year, but most present by 5 years.
Portal hypertension usually manifests by splenomegaly, signs of esophageal varices (hematemesis or melena), ascites, encephalopathy, or hemorrhoids.
In most children with splenomegaly as a manifestation (usually found on routine examination), the patient looks well, growth is normal, and no signs or symptoms of jaundice or liver disease are obtained.
The cause of portal hypertension secondary to cavernous venous transformation of the portal vein is idiopathic in half of cases. Among idiopathic cases, some findings suggest a more widespread congenital developmental insult. More than one-third of prehepatic cases are attributable to a neonatal insult, dehydration, umbilical catheters, or infection.
Our patient was hospitalized twice before age 4 months--for viral meningitis and for a severe infection with dehydration.
TREATMENT: Although some gastroenterologists recommend the initiation of propranolol in an attempt to reduce the portal venous pressure, we elected expectant observation.
Fortunately, many of these cases resolve spontaneously in early adulthood, as long as no bleeding from the varices occurs. Our patient is currently asymptomatic, and with a "spleen guard," is playing basketball again.
Case contributed by Dr. Stan L. Block of Bardstown, Ky.
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|Article Type:||Brief Article|
|Date:||Jul 1, 2002|
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