Approaches to the diagnosis of hepatocellular carcinoma.

The advent of screening programs for hepatocellular carcinoma in patients with chronic viral hepatitis and cirrhosis has resulted in detection of smaller and smaller lesions in the liver. Some of these are small carcinomas, but many are not malignant in nature or are potential precursors to malignancy. Neither radiology nor biopsy can be used confidently to distinguish between these possibilities when the lesions are smaller than approximately 1.5 cm in diameter. Therefore, diagnostic algorithms must be developed to assist physicians in investigating these small lesions and deciding when they are truly malignant, when treatment is necessary, or whether a watchful waiting course is appropriate. The diagnostic difficulties are presented, with examples of diagnostic algorithms that may be helpful in managing these patients.