Sampling Error and Intraobserver Variation in Liver
Biopsy in Patients With Chronic HCV Infection
Arie Regev, M.D., Mariana Berho, M.D., Lennox J. Jeffers, M.D., Clara Milikowski, M.D.,
Enrique G. Molina, M.D., Nikolaos T. Pyrsopoulos, M.D., Zheng-Zhou Feng, M.D.,
K. Rajender Reddy, M.D., and Eugene R. Schiff, M.D.
Center for Liver Diseases, University of Miami School of Medicine, Miami, Florida; Department of
Pathology, Jackson Memorial Hospital, Miami, Florida; Department of Pathology, VA Medical Center,
Miami, Florida; and Division of Gastroenterology, University of Pennsylvania, Philadelphia, Pennsylvania
OBJECTIVES: Needle liver biopsy has been shown to have a
high rate of sampling error in patients with diffuse paren-
chymal liver diseases. In these cases, the sample of liver
tissue does not reflect the true degree of inflammation,
fibrosis, or cirrhosis, despite an adequate sample size. The
aim of this study was to determine the rate and extent of
sampling error in patients with chronic hepatitis C virus
infection, and to assess the intraobserver variation with the
commonly used scoring system proposed by Scheuer and
modified by Batts and Ludwig.
METHODS: A total of 124 patients with chronic hepatitis C
virus infection underwent simultaneous laparoscopy-guided
biopsies of the right and left hepatic lobes. Formalin-fixed
paraffin-embedded sections were stained with hematoxylin
and eosin and with trichrome. The slides were blindly coded
and randomly divided among two hepatopathologists. In-
flammation and fibrosis were scored according to the stan-
dard grading (inflammation) and staging (fibrosis) method
based on the modified Scheuer system. Following the inter-
pretation, the slides were uncoded to compare the results of
the right and left lobes. Fifty of the samples were blindly
resubmitted to each of the pathologists to determine the
intraobserver variation.
RESULTS: Thirty of 124 patients (24.2%) had a difference of
at least one grade, and 41 of 124 patients (33.1%) had a
difference of at least one stage between the right and left
lobes. In 18 patients (14.5%), interpretation of cirrhosis was
given in one lobe, whereas stage 3 fibrosis was given in the
other. A difference of two stages or two grades was found
in only three (2.4%) and two (1.6%) patients, respectively.
Of the 50 samples that were examined twice, the grading by
each pathologist on the second examination differed from
the first examination in 0% and 4%, and the staging differed
in 6% and 10%, respectively. All observed variations were
of one grade or one stage.
CONCLUSIONS: Liver biopsy samples taken from the right
and left hepatic lobes differed in histological grading and
staging in a large proportion of chronic hepatitis C virus
patients; however, differences of more than one stage or
grade were uncommon. A sampling error may have led to
underdiagnosis of cirrhosis in 14.5% of the patients. These
differences could not be attributed to intraobserver varia-
tion, which appeared to be low. (Am J Gastroenterol 2002;
97:2614–2618. © 2002 by Am. Coll. of Gastroenterology)
INTRODUCTION
Liver biopsy is an important tool in the evaluation of pa-
tients with chronic hepatitis C virus (HCV) infection. Ac-
curacy and reproducibility are essential in the histological
assessment of disease severity in these patients, yet, needle
liver biopsy has been shown to be associated with a high rate
of sampling error in patients with diffuse parenchymal liver
diseases (1–4). Sampling error is defined as the deviation of
a sample from the population (or tissue) from which it was
taken (5). The possibility of sampling error in a liver biopsy
is conceivable because the tissue obtained with a biopsy
needle represents a very small portion (approximately one
of 50,000) of the entire liver mass (6). A sampling error
may, therefore, occur despite an adequate sample size and a
satisfactory number of portal tracts. Consequently, the in-
formation in the sample may not fully reflect the true patho-
logical picture. Sampling error has been shown to exist in
needle liver biopsy, in respect to severity of inflammation
(1, 3, 7), degree of fibrosis (1, 7), and presence of cirrhosis
(1, 4, 7–11), or granulomas (1). Although several studies
have addressed the question of sampling error in liver bi-
opsy, most of them used classification systems that have
since been abandoned, and none of them addressed chronic
HCV infection specifically (1, 4, 6–14).
The Scheuer system (15), modified by Batts and Ludwig
(16, 17) (Table 1), has been adopted by many pathologists
and hepatologists for the routine histological evaluation of
patients with chronic HCV infection. Although it is widely
used, there are only limited data regarding the reliability of
this classification system.
This study was designed to determine the rate and extent
of sampling error of needle liver biopsy in patients with
THE AMERICAN JOURNAL OF GASTROENTEROLOGY Vol. 97, No. 10, 2002
© 2002 by Am. Coll. of Gastroenterology ISSN 0002-9270/02/$22.00
Published by Elsevier Science Inc. PII S0002-9270(02)04396-4

chronic hepatitis C, using the modified Scheuer classifica-
tion. The data were also analyzed to evaluate the intraob-
server variation in the histological grading and staging ac-
cording to this classification system.
PATIENTS AND METHODS
Patients
Consecutive patients with chronic HCV infection, who un-
derwent laparoscopy-guided liver biopsies before treatment,
were enrolled in this study. All the patients had abnormal
ALT for at least 6 months before the biopsy. A diagnosis of
HCV infection was based on positive HCV antibodies by
third generation enzyme immunoassay (EIA) or recombi-
nant immunoblot assay and a positive HCV RNA test.
Patients with history of excessive alcohol intake and those
with serological markers for hepatitis B virus infection,
autoimmune hepatitis, or primary biliary cirrhosis, were
excluded from the study. Patients with histopathological
findings suggestive of another liver disease (autoimmune,
alcoholic, nonalcoholic steatohepatitis, or drug-induced
hepatitis) were also excluded. None of the patients had been
treated for chronic hepatitis C. All the patients signed in-
formed consent for the procedure.
Study Design and Scoring System
Each patient underwent liver biopsies from the right and left
hepatic lobes, during a laparoscopic examination, using an
automatic 16-gauge Tru-Cut needle (biopsy gun), (Medical
Technology, Gainesville, FL). All the specimens examined
in this study were of adequate size according to the most
widely accepted criteria for a satisfactory liver biopsy (at
least 1.5 cm in length and with five or more portal zones)
(18, 19). Formalin-fixed paraffin-embedded sections were
stained with hematoxylin and eosin and with Masson’s
trichrome. The slides were blindly coded and reviewed
randomly by two hepatopathologists. Both pathologists
were very experienced with liver pathology, and were in-
volved in liver pathology on a day-to-day basis. One of the
pathologists reviewed slides from 50 patients, and the other
reviewed slides from 74 patients. The histological findings
were assessed according to the standard grading and staging
method based on the Scheuer system (15) modified by Batts
and Ludwig (16, 17) (Table 1). Following the interpretation,
the slides were uncoded to compare the results of the right
and left lobes. Slides from 50 of the patients were blindly
resubmitted to each of the pathologists, after an interval of
3–4 months, for a second observation, to determine the
intraobserver variation.
Statistical Analysis
Percentage of concordance was calculated for observations
made for the right and left lobes, as well as for intraobserver
variation. The agreement between observations (right vs left
lobes, and each pathologist vs himself) was assessed using
the
coefficient, where

1 indicates perfect agreement,
1 
 0.80 almost perfect, 0.80 
 0.60 substantial,
0.60 
 0.40 moderate, 0.40 
 0.20 fair, 0.20 

 0 slight, and

0 no agreement (20–22).
The possibility of association between the level of his-
topathological score and the hepatic lobe was assessed by
Wilcoxon test. This test was used to determine whether
samples obtained from the right hepatic lobe were consis-
tently graded or staged higher (or lower) compared with the
left lobe. A two-sided p value of 0.05 was considered to
indicate a statistically significant difference.
RESULTS
A total of 124 patients, 55 (44%) women and 69 (56%) men,
were included in this study. Median age was 47 (range
20–77).
Grade of Necroinflammatory Activity
None of the samples was graded as 0. Eighty-five (68.6%)
of 124 samples taken from the right lobe were graded as
either 1 or 2, whereas 39 (31.4%) were graded as 3 or 4.
Similarly, of the 124 samples taken from the left lobe, 84
(67.7%) were graded as 1 or 2, whereas 40 (32.3%) samples
were graded as 3 or 4. The mean grade of necroinflamma-
Table 1. The Modified Scheuer System*
Necroinflammatory Activity Fibrosis and Cirrhosis
Grade Portal/Periportal Activity Lobular Activity Stage Fibrosis
0 None or minimal None 0 Normal connective
tissue
1 Portal inflammation Minimal, occasional
spotty inflammation
1 Fibrous portal expansion
2 Mild piecemeal necrosis Mild; focal necrosis 2 Periportal or rare portal-
portal septa
3 Moderate piecemeal
necrosis
Moderate; noticeable
hepatocellular
change
3 Fibrous septa with
architectural distortion
4 Severe piecemeal
necrosis
Severe; diffuse
hepatocellular
damage
4 Cirrhosis
* From reference 16.
2615AJG – October, 2002 Sampling Error in Liver Biopsy