Agenesis of the right lobe of the liver.

In five patients with agenesis of the right lobe of the liver, computed tomography or sonography demonstrated absence of the right lobe with compensatory hypertrophy of other segments. In three patients, the caudate lobe was also absent. The radiologic differential diagnosis includes lobar atrophy due to cirrhosis or hilar cholangiocarcinoma. Nineteen other cases have been reported in the world literature since 1956. This interesting congenital anomaly may be associated with biliary tract disease (12 patients), portal hypertension (seven patients), and other congenital anomalies (four patients), or it may be an incidental finding (five patients).