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86<br />
ABDOMINAL ULTRASOUND<br />
A<br />
C<br />
Figure 4.9 cont’d (C) On administration of microbubble<br />
contrast agent, the lesion in (B) demonstrates peripheral,<br />
globular enhancement, with gradual centripetal filling,<br />
consistent with haemangioma.<br />
well-defined, hyperechoic mass are due to benign<br />
haemangioma. Follow-up scans will demonstrate<br />
no appreciable change over time. However, where<br />
doubt exists, it is useful to refer the patient for further<br />
imaging, such as MRI scanning, to characterize<br />
the lesion confidently.<br />
Administration of an ultrasound contrast agent is<br />
also useful in lesion characterization and a haemangioma<br />
usually demonstrates a peripheral, nodular<br />
enhancement pattern in the arterial phase, with<br />
gradual centripetal filling (Fig. 4.9C). 5<br />
Adenoma<br />
The hepatic adenoma is a benign focal lesion consisting<br />
of a cluster of atypical liver cells (Fig. 4.10).<br />
Within this, there may be pools of bile or focal<br />
areas of haemorrhage or necrosis. This gives rise to<br />
a heterogeneous, patchy echotexture. The smaller<br />
ones tend to be homogeneous with a smooth texture.<br />
They are usually less reflective than a haemangioma<br />
and may have similar reflectivity to the<br />
surrounding liver parenchyma.<br />
Larger adenomas may contain vigorous arterial<br />
flow on Doppler, but this is not pathognomonic and<br />
does not differentiate it from a malignant lesion.<br />
B<br />
Figure 4.10 (A) Adenoma in segment 5 in a young<br />
woman on the oral contraceptive pill. (B) An unusual<br />
example of cystic degeneration in a large adenoma.<br />
Clinical features<br />
There is a particularly strong association between<br />
hepatic adenoma and use of the oral contraceptive<br />
so these masses tend to present in younger women.<br />
Adenomas are also associated with glycogen storage<br />
disease.<br />
They may cause pain, particularly if they haemorrhage,<br />
and may be palpable. Surgical removal is the<br />
management of choice, although they occasionally<br />
regress if the oral contraceptive is discontinued.<br />
Ultrasound is useful in monitoring patients with<br />
glycogen storage disease for changes in the charac-
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