الفهرس 
Anatomy of the biliary system
The dorsal (Caudate) lobe (segment l)Only 14 pages are availabe for public view
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Abstract
Cholangiocarcinoma is a malignant tumor of the bile ducts,
and it is a rare tumor, its incidence in the United States is about
1.0 per 100,000 people per year. Cholangiocarcinoma may be
inside the liver (intrahepatic) that is less common, or outside in
the extrahepatic biliary ducts that is divided into distal or
proximal. Distal cholangiocarcinoma originates in the CBD from
the upper border of pancreas to the ampulla of Vater. The
Proximal cholangiocarcinoma (i.e., Klatskin’s tumor) is more
common than distal one, and it originates at the bifurcation of
hepatic ducts.
The majority of the tumor is ductal adenocarcinoma (95%)
and the rest is squamous cell carcinoma. There is no a clear cause
of cholangiocarcinoma, but chronic irritation as with chronic liver
fluke infection, or with primary sclerosing cholangitis may play a
role in hyperplasia and malignant transformation. Gall stones,
nowadays not believed to be a risk factor of cholangiocarcinoma.
But exposure to some toxins and inflammatory bowel diseases are
risk factors.
The tumor has no confined symptoms and signs, but
jaundice is the most common clinical pictures. If the tumor
localized in one hepatic duct, jaundice won’t be obvious. In
contrast if the tumor infiltrates the common hepatic duct or
common bile duct, jaundice will be the first sign. Others
symptoms may be found, such as pruritis, abdominal pain, weight
loss, dark urine and clay colored stool.
Some laboratory findings are found, as Hyperbilrubinemia,
leukocytosis, elevated serum alkaline phosphatase and gammaglutamyl transpeptidase. Estimation of tumor marker stays
disputable, but may be used as carbohydrate antigen 19-9 (CA 19-
9) and carcinoembryonic antigen (CEA).
Ultrasonography of the abdomen usually shows dilatation
of the intrahepatic bile ducts or extrahepatic one, that is a good
hint for further investigations. CT scan also may give more help
in diagnosing a tumor mass. MRI/MRCP has a great sensitivity in
diagnosing a malignant bile obstruction. ERCP is helpful to
diagnose a malignant stricture and also in a therapeutic use.
New modalities are updated to ensure the diagnosis, such as
endoscopic ultrasonography, Fine needle aspiration guided by the
EUS, Fluorescent in situ hybridization with digital imaging study.
All these techniques are to determine the histopathology of the
tumor. PET scan also may be helpful in determining the distant
metastasis.
The best treatment of cholangiocarcinoma is the surgical
one, unless the tumor is unresectable. Intrahepatic
cholangiocarcinoma is treated by liver resection, perihilar
cholangiocarcinoma is treated by local tumor excision with portal
lymphadenectomy, cholecystectomy, common bile duct excision,
and bilateral Roux-en-Y hepaticojejunostomy, if the tumor
involves right or left hepatic duct, is treated by right or left
hepatic lobectomy, respectively. And distal cholangiocarcinoma
is treated by Whipple’s operation. Nowadays laparoscopic
Whipple’s operation is available in specific centers.
Unfortunately, the tumor first presentation is late and most
of patients show unresectable tumor. So many palliative measures
are described for those patients, as percutaneous placement of
expandable metal stents for drainage, Photodynamic therapy,
intra-luminal brachytherapy, Chemotherapy and radiotherapy.
Also surgical methods are described for palliation, like
hepaticojejunostomy for unresectable proximal tumor and
choledochojejunostomy for unresectable distal tumor.
Recently targeted therapies are described and showing
promising results. Examples of these agents include, EGFR and
VEGF. They based on the understanding of the molecular base of
the tumor, and trying to stop the tumor cell proliferation by
interfering with the signal transported from the receptor to the
DNA of the cell.