Distinctive expression of CD133 between intraductal papillary neoplasms of the bile duct and bile duct adenocarcinomas.
OBJECTIVE
Intraductal papillary neoplasm of the bile duct (IPNB), a novel entity of biliary disease, is recently advocated as the counterpart of pancreatic intraductal papillary mucinous neoplasm (IPMN) because both are in common with a large amount of mucin production and papillary growth. Based on our recent finding that expression of CD133, a cancer stem cell marker, is lacking in pancreatic IPMN, we herein focused on CD133 expression of IPNB in comparison with intrahepatic cholangiocellular carcinoma (IHCCC) or hilar bile duct cancer (HBDC).


METHODS
Expression of CD133 protein was immunohistochemically determined in patients with IPNB (n = 7), IHCCC (n = 16) or HBDC (n = 8). In addition, morphological and immunohistochemical mucin expression patterns were characterized in IPNB, and clinicopathological features including prognosis were compared between IPNB and other biliary tumors.


RESULTS
The IPNB group included significantly more females than the other two groups, and had a longer survival time. While no CD133 expression was observed in IPNB tumor, 16.4% of cancer cells in IHCCC and 17.2% of cells in HBDC expressed CD133. Among seven patients with IPNB, six (86%) were morphologically the pancreatobiliary type and four of six showed mucin expression pattern of the typical pancreatobiliary type (MUC1+/MUC2-/MUC5AC+).


CONCLUSIONS
Loss of CD133 expression supports the hypothesis that IPNB is a counterpart of pancreatic IPMN with a differing carcinogenesis from conventional bile duct adenocarcinomas.
Department of Surgery, Division of Hepato-Billiary-Pancreatic Surgery             Division of Diagnostic Pathology, Kobe University Graduate School of Medicine             Department of Biophysics, Division of Medical Chemistry, Kobe University Graduate School of Health Sciences             Department of Internal Medicine, Kobe Medical Center, Kobe             Department of Pathology, Saitama Medical University International Medical Center, Saitama, Japan.
Izuru
I
Ohtsubo
Tetsuo
T
Ajiki
Yuichi
Y
Hori
Sae
S
Murakami
Kazuya
K
Shimizu
Tomoo
T
Itoh
Michio
M
Shimizu
Takumi
T
Fukumoto
Yonson
Y
Ku