Diagnostic ultrasound ( PDFDrive )

CHAPTER 4 The Liver 119
A
B
C
D
FIG. 4.54 Fatty Tumors of Liver: Lipoma and Angiomyolipoma. (A) Sonogram shows a highly echogenic, solid focal liver mass, which initially
suggests a hemangioma. The discontinuity of the diaphragm echo caused by the altered rate of sound transmission is a clue to the correct
diagnosis. (B) Conirmatory computed tomography scan shows the fat density of the mass, a conirmed hepatic lipoma. (C) and (D) Another highly
echogenic and slightly exophytic mass in the liver, initially suggesting a hemangioma. (A and B with permission from Garant M, Reinhold C. Residents’
corner. Answer to case of the month #36. Hepatic lipoma. Can Assoc Radiol J. 1996;47[2]:140-142. 242 C and D with permission from Wilson SR.
The liver. In Gastrointestinal disease. 6th series. Test and syllabus. Reston Virginia: American College of Radiology; 2004. 26 )
is present. Serum alpha feto-protein levels are frequently elevated.
Treatments and earlier diagnosis have improved over time. Among
HCC cases diagnosed from 1998 to 2007, transplant recipients
experienced 84% 5-year survival. Cases with tumors less than
3 cm in size that received radiofrequency ablation had a 5-year
survival rate of 53%, while cases undergoing liver resection had
a 5-year survival rate of 47%. Overall the HCC survival rate
from 1998 to 2007 was 18%, whereas the survival rate was 7%
among cases without reported invasive surgery or local tumor
destruction. 171
Pathologically, HCC occurs in the following three forms:
• Solitary tumor
• Multiple nodules
• Difuse iniltration
here is a propensity toward venous invasion. he portal vein
is involved in 30% to 60% of cases and more oten than the
hepatic venous system. 172-174
he sonographic appearance of HCC is variable. he masses
may be hypoechoic, complex, or echogenic. Most small (<5 cm)
HCCs are hypoechoic (Fig. 4.55A), corresponding histologically
to a solid tumor without necrosis. 175,176 A thin, peripheral
hypoechoic halo, which corresponds to a ibrous capsule, is seen
most oten in small HCCs. 177 With time and increasing size, the
masses tend to become more complex and inhomogeneous as
a result of necrosis and ibrosis (Fig. 4.55E). Calciication is
uncommon. 178 Small tumors may appear difusely hyperechoic,
secondary to fatty metamorphosis or sinusoidal dilation (Fig.
4.55C), making them indistinguishable from focal fatty iniltration,