Diagnostic ultrasound ( PDFDrive )

124 PART II Abdominal and Pelvic Sonography
A
B
C
FIG. 4.58 Multimodality Approach to Diagnosis
of Hepatocellular Carcinoma (HCC). Small HCC in
59-year-old man with ethanol and hepatitis C virus
cirrhosis. (A) Magnetic resonance imaging shows no
mass on T2-weighted images and no hypervascularity
on enhanced scan. (B) Baseline sonogram shows a
single hypoechoic nodule in the right lobe of the cirrhotic
liver. (C) Contrast-enhanced ultrasound (CEUS) arterial
phase image shows clear hypovascularity of the mass.
The mass quickly became isovascular and did not show
washout. Familiarity with the variations of enhancement
patterns of HCC on CEUS prompted request for biopsy,
which showed a moderately differentiated HCC. (With
permission from Wilson S, Burns P. Microbubbleenhanced
US in body imaging: what role? Radiology.
2010;257[1]:24-39. 148 )
EHE begins as multiple hypoechoic nodules, which grow and
coalesce over time, forming larger, conluent masses that tend
to involve the periphery of the liver. Foci of calciication may
be present. 193,194 he hepatic capsule overlying the lesions of
EHE may be retracted inward, secondary to ibrosis incited
by the tumor; this unusual feature is highly suggestive of the
diagnosis. Importantly, peripheral postchemotherapy metastases
and tumors causing biliary obstruction and segmental atrophy
may have a similar appearance. he diagnosis of hepatic EHE is
made by percutaneous liver biopsy and immunohistochemical
staining.
Metastatic Liver Disease
In the United States, metastatic liver disease is 18 to 20 times
more common than HCC. Detection of metastasis greatly alters
the patient’s prognosis and oten the management. he incidence
of hepatic metastases depends on the type of primary tumor
and its stage at initial detection. At autopsy, 25% to 50% of patients
dying from cancer have liver metastases. Patients with short-term
survival (<1 year) ater initial detection of liver metastases are
those with HCC and carcinomas of the pancreas, stomach, and
esophagus. Patients with longer-term survival are those with
head and neck carcinomas and carcinoma of the colon. Most
patients with melanoma have an extremely low incidence of
hepatic metastases at diagnosis. Liver involvement at autopsy,
however, may be as high as 70%.
he most common primary tumors resulting in liver
metastases, in decreasing order of frequency, are gallbladder,
colon, stomach, pancreas, breast, and lung. Most metastases to
the liver are blood-borne through the hepatic artery or portal
vein, but lymphatic spread of tumors from stomach, pancreas,
ovary, or uterus may also occur. he portal vein provides direct
access to the liver for tumor cells originating from the gastrointestinal
tract and probably accounts for the high frequency
of liver metastases from organs that drain into the portal
circulation.