Diagnostic ultrasound ( PDFDrive )

186 PART II Abdominal and Pelvic Sonography
A
B
FIG. 6.25 Peripheral Cholangiocarcinoma. (A) Ultrasound and (B) CT images depict a solid mass encasing but not obliterating the right and
middle hepatic veins, a inding suggestive of peripheral cholangiocarcinoma.
A
B
FIG. 6.26 Intraductal Papillary, Mucin-Producing Tumor of Bile Ducts. (A) Ultrasound and (B) MRCP images show papillary tumor arising
from the common hepatic duct (arrow) and causing diffuse ductal dilation due to excessive mucin production.
complex anatomy of the porta hepatis, with structures lying just
outside the liver and surrounded by connective tissue. Ultrasound
plays an important role in both detection and staging of hilar
cholangiocarcinomas because it is oten the irst modality used
in assessment of these tumors. Furthermore, ultrasound is oten
performed before any biliary manipulation and stent placement.
Because biliary intervention oten obscures the intraductal disease
and causes secondary bile duct thickening, sonography may be
the only cross-sectional modality to assess the unmanipulated
ducts. Most patients with hilar cholangiocarcinoma present for
a sonographic evaluation with jaundice, pruritus, and elevated
cholestatic liver parameters, or with vague symptoms and
elevated serum alkaline phosphatase or γ-glutamyl transpeptidase
levels.
Patterns of Tumor Growth. Hilar cholangiocarcinomas
oten begin in either the right or the let bile duct and extend
both proximally into higher-order branches and distally into the
CHD and contralateral bile ducts. he spread of tumor may be
subendothelial, or within the peribiliary connective tissue, leading
to obstruction or irregular ductal narrowing. he tumors also
extend outside the ducts to involve adjacent portal vein and
arteries. Chronic obstruction, especially if accompanied with
portal vein involvement, leads to atrophy of the involved lobe.
Nodal disease oten begins in the porta hepatis and within the
hepatoduodenal ligaments (local nodes) and extends to celiac,
superior mesenteric, peripancreatic, and posterior pancreatoduodenal
stations (distant nodes). 65 Metastases are usually to
the liver and peritoneal surfaces.
Treatment and Staging. Curative treatment of cholangiocarcinoma
requires surgical resection; the vast majority of patients
with unresectable disease die within 12 months of diagnosis. 51
he current surgical approach to patients with hilar cholangiocarcinoma
is resection of the involved lobe with extensive hilar
dissection to remove tumor extending to the contralateral lobe
(extended lobectomy). A biliary-enteric anastomosis is created
to allow bile drainage. Currently, no widely used staging systems