MCQ 29

A 35 year old  HIV infected homosexual man presents with fever, pain of the right upper quadrant, and a CT scan of the liver that shows a 10 cm, oval, hypoechoic cyst in the right lobe. An ELISA assay detects the presence of antibodies to Entamoeba histolytica; cysts from the same organism are found in a stool specimen. Which of the following is the most appropriate next step in the management?

a. Administration of metronidazole
b. Administration of chloroquine
c. Drainage of the hepatic lesion for therapeutic purposes
d. Aspiration of the hepatic lesion for diagnosis
e. Hepatic resection

Answer and explanation

The answer is 'a'

AIDS patients particularly homosexual men have a significant incidence of infection with Entamoeba histolytica, though they are frequently asymptomatic. The most common amebic related syndrome is that of colitis(though this patient doesn't have it)

Extraintestinal infection by the organism E.histolytica usually involves the liver. While the symptoms (fever, pain in the right upper quadrant, and pleural effusion) and the radiologic findings (hypoechoic hepatic cysts) are nonspecific and could also be seen in bacterial abscesses or cancer, such symptoms in a patient with positive serology are quite helpful in making the diagnosis of invasive amebiasis. For that reason, no further diagnoistic studies are indicated in the patient. Except in patient with threatened imminent rupture of the cyst, drainage or aggressive aspiration is not necessary.

The drug of choice is metronidazole, though the less effective agent chloroquine might also be considered.