Sampling variability and its influence on the diagnostic yield of percutaneous needle biopsy of the liver.

In an investigation to determine the influence of sampling variability on the diagnostic yield of liver biopsy, 3 consecutive samples were obtained from each of 75 patients by redirecting the biopsy needle through a single entry site. In 14.7% of patients all 3 specimens were normal, and in 36% there were similar abnormalities in all 3 specimens. In the other patients, sampling variability between specimens was present. In those patients with cirrhosis, hepatocellular carcinoma, metastatic carcinoma, or hepatic granulomas the histological abnormality was present in all 3 biopsy specimens in only 50%, 54.5%, 50%, and 18.8% of patients, respectively. No complications were recorded. These findings show that important pathology can be overlooked if only a single biopsy specimen is taken, and that the method of obtaining 3 consecutive specimens improves the diagnostic yield of liver biopsy without an associated increase in complications.