Amebic liver abscess. Differential diagnosis of cholecystitis.

Among patients presenting with pain and tenderness in the right upper quadrant were 75 with cholelithiasis (13 male, 2 under age 50) and 9 with amebic hepatic abscess (6 male, all under age 45). The differential diagnosis of cholelithiasis versus liver abscess was accurately made by prompt sonography and hepatobiliary scintigraphy. Amebic abscess was confirmed by positive serum ameba titers. Presenting symptoms and results of laboratory studies of patients with amebic abscess were indistinguishable from those of patients with cholecystitis. It is concluded that an accurate diagnosis of amebic liver abscess in the differential diagnosis of cholecystitis can be made by sonography and hepatobiliary imaging. Also, in endemic areas of the southwestern United States, amebic abscess should be strongly considered in the differential diagnosis of patients presenting with pain and tenderness in the right upper quadrant and is more common than cholecystitis in young men.