The availability and increased accessibility of abdominal imaging has led to increased diagnosis of asymptomatic liver lesions known in the trade as ‘incidentalomas’. The next question that arises is what to do about them?
Jonathan Koea, in his article in this month’s HPB, has examined the referral patterns and outcomes of a large number of such lesions in Auckland, New Zealand. He found that incidentalomas accounted for 10% of all liver cases referred to his practice. The majority of these lesions were benign, but 10% of all lesions turned out to be malignant. Radiological subclassification on the basis of perfusion on contrast imaging separated cholangiocarcinomas (low attenuation) from other malignant hepatocellular carcinoma and metastases (high attenuation) and interestingly these formed 10% of both low and high attenuating lesions.
Lurking among the adenomas, focal nodular hyperplasia, inflammatory nodules, haemangiomas and cysts will be some malignant cancers and it is crucial to have your radar switched on to detect these. Quality imaging is the key to defining incidentalomas and contrast MRI scans are particularly helpful in obtaining a confident diagnosis of many of these lesions. In an unfiltered referral practice the rule of 10s is well worth remembering; 10% of your practice will be incidentalomas and 10% will prove to be malignant.