HEPATIC ADENOMA HEPATIC CALCIFICATION

Adenoma
The hepatic adenoma is a benign focal lesion consisting of a cluster of atypical liver cells. Within this, there may be pools of bile or focal areas of haemorrhage or necrosis. This gives rise to a heterogeneous, patchy echotexture. The smaller ones tend to be homogeneous with a smooth texture. They are usually less reflective than a haemangioma and may have similar reflectivity to the surrounding liver parenchyma. Larger adenomas may contain vigorous arterial flow on Doppler, but this is not pathognomonic and does not differentiate it from a malignant lesion.

Clinical features
There is a particularly strong association between hepatic adenoma and use of the oral contraceptive so these masses tend to present in younger women. Adenomas are also associated with glycogen storage disease. They may cause pain, particularly if they haemorrhage, and may be palpable. Surgical removal is the management of choice, although they occasionally regress if the oral contraceptive is discontinued. Ultrasound is useful in monitoring patients with glycogen storage disease for changes in the characteristics of their adenomas, as malignant degeneration is a possible feature.

Hepatic calcification
Calcification occurs in the liver as a result of some pathological processes and may be seen following infection or parasitic infestation. It may be focal (usually the end stage of a previous abscess, haematoma or granuloma) which usually indicates that the lesion in question is no longer active. It may also be seen within some metastases. Calcification may also be linear in nature, following the course of the portal tracts. This can be associated with old TB or other previous parasitic infestations.

Occasionally hepatic calcification is seen in children or in the fetus. This is usually not a significant finding but prenatal infection should be excluded with a TORCH (toxoplasmosis, rubella, cytomegalovirus and HIV) screen. Calcification, which casts a strong and definite shadow, should be distinguished from air in the biliary tree, which casts a reverberative shadow and is usually associated with previous biliary interventions, such as ERCP, sphincterotomy or stent placement.