Isolated idiopathic bile ductular hyperplasia in patients with persistently abnormal liver function tests.
OBJECTIVE
In routine examination of liver biopsies isolated ductular hyperplasia (IDH) may be the only histopathological change. Here we describe the clinical and immunophenotypic features of a number of cases retrospectively identified reviewing consecutive liver biopsies from five Italian centers over 4 years.


METHODS
We reviewed 1235 cases biopsied for chronic liver disease (1078 for viral hepatitis). Records of cases fulfilling the inclusion criteria for IDH were reviewed to identify possible aetiologies. Biopsies showing IDH and control biopsies were studied by immunohistochemistry for cytokeratin-7, epithelial-membrane-antigen (EMA), neural-cell-adhesion-molecule (NCAM), Ki-67.


RESULTS
Out of 70 biopsies fulfilling IDH criteria, 16 (22.8%) were of unknown aetiology. Patients with idiopathic IDH (age 38.2+/-11 years) were asymptomatic with mild, long-lasting ALT and/or gammaGT increases. A significant increase of well-differentiated (EMA-positive; NCAM-negative) bile ductules localized at the portal interface and inside the lobule was found in idiopathic IDH.


CONCLUSIONS
Idiopathic IDH was present in 10% of adults biopsied for persistent mild liver function test abnormalities unrelated to viral hepatitis. In contrast with the ductular reaction seen in many forms of liver disease, it is characterized by well-differentiated hyperplastic ductules in absence of significant inflammation, and may represent a non-specific pattern of reaction to mild liver damages.
Sonzogni
Aurelio
A
Department of Pathology, Ospedali Riuniti, Bergamo, Italy.
Colloredo
Guido
G
Fabris
Luca
L
Cadamuro
Massimiliano
M
Paris
Bruno
B
Roffi
Luigi
L
Pozzi
Massimo
M
Bovo
Giorgio
G
Del Poggio
Paolo
P
Portmann
Bernard C
BC
Strazzabosco
Mario
M
D000293:Adolescent; D000328:Adult; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006965:Hyperplasia; D053552:Keratin-7; D007633:Keratins / Q000378:metabolism; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism; D012189:Retrospective Studies
C507497:KRT7 protein, human; D053552:Keratin-7; D018396:Mucin-1; D019006:Neural Cell Adhesion Molecules; D007633:Keratins