Imaging and clinical characteristics of focal atrophy of segments 2 and 3 in primary sclerosing cholangitis

Background and Aims: Focal atrophy in primary sclerosing cholangitis (PSC) is usually thought to result from severe biliary stricture and focal biliar y cirrhosis. Atrophy of the left lateral segments (segments 2 and 3) are st riking when observed grossly. This type of atrophy may be subtle on cross-s ectional imaging and by endoscopic retrograde cholangiopancreatography (ERC P) because of the peripheral location and compensatory hypertrophy of other parts of the liver. We examined 44 consecutive PSC patients to determine t he incidence and clinical characteristics of this abnormality, and to corre late imaging studies with the gross appearance. Methods: We reviewed all cases of PSC encountered over a 3 year period asce rtained from the liver disease registry. Magnetic resonance imaging or CT i mages were re-examined for evidence of segment 2 and 3 atrophy. Results: Four of 44 patients had focal segment 2 and 3 atrophy. These four had been confirmed laparoscopically or by inspection of the liver explant. The remaining segments of the liver were relatively spared of injury in two of the patients, and three of the four patients had preserved synthetic fu nction without evidence of portal hypertension. While the abnormality is cl early visible on cross-sectional imaging, its peripheral location caused it to be an unobtrusive. Likewise, ERCP did not clearly reveal the abnormalit y on initial inspection. Conclusions: We conclude that focal atrophy of segments 2 and 3 is a someti mes early and subtle finding in PSC that may be overlooked in cross-section al imaging or ERCP unless specifically sought. (C) 2001 Blackwell Science A sia Pty Ltd.