Diagnostic ultrasound ( PDFDrive )

CHAPTER 4 The Liver 115
A
B
C
D E F
FIG. 4.49 Classic Focal Nodular Hyperplasia (FNH) on Contrast-Enhanced Ultrasound (CEUS). (A) Sagittal image of the liver in an asymptomatic
woman shows a slightly exophytic very round isoechoic mass in the liver. (B) Addition of color Doppler shows strong central signal. (C)-(E) Sequential
frames in the arterial phase show a stellate vessel morphology and centrifugal iling, from the center of the mass to its periphery. (F) Hypervascular
mass has sustained enhancement, appearing brighter than the liver at 4 minutes, conirming the benign nature of this mass. See also Videos 4.7
and 4.8.
direction (Fig. 4.49 and Videos 4.7 and 4.8). Arterial phase
enhancement is homogeneous and in excess of the adjacent liver.
Portal venous enhancement is sustained such that lesion enhancement
equals or exceeds that of adjacent liver with a nonenhancing
scar (Video 4.5). Infrequently, FNH may show washout, which
is oten weak and delayed. An unenhanced scar may be seen in
both arterial and portal phases. Ultrasound alone should be able
to suggest the presence of these insigniicant lesions without
referral for further imaging.
Sulfur colloid scanning is invaluable in patients with suspect
FNH because 50% of lesions will take up sulfur colloid similar
to the adjacent normal liver, and another 10% will be “hot.”
herefore only 40% of patients with FNH will lack conirmation
of their diagnosis ater performing a sulfur colloid scan. 160,161 In
these patients, CECT or MRI may be performed for diagnosis.
Biopsy may be required in a minority of patients with FNH
who do not have a hot or a warm lesion on sulfur colloid scanning,
especially if CT or MRI features are not speciic. Cytology is
not conirmatory because normal hepatocytes may be found in
normal liver, adenoma, and FNH. Core liver biopsy is required
to show the disorganized pattern characteristic of this pathology.
Because FNH rarely leads to clinical problems and does not
undergo malignant transformation, conservative management
is recommended. 162
Hepatic Adenoma
Hepatic adenoma is the most important benign tumor of the
liver because of its frequency and potential for complications
that are life threatening, including bleeding and malignant
transformation. Hepatic adenomas are much less common than
FNH. However, a dramatic rise in their incidence since the 1970s
clearly established a link to oral contraceptive use. As expected,
therefore, hepatic adenomas are more common in women. he
tumor may be asymptomatic, but oten the patient or the physician
feels a mass in the right upper quadrant. Pain may occur as a
result of bleeding or infarction within the lesion. he most
alarming manifestation is shock caused by tumor rupture and
hemoperitoneum. Hepatic adenomas have also been reported