Diagnosis of small hepatocellular carcinoma by computed tomography: correlation of CT findings and histopathology.

The diagnostic value of computed tomography (CT) scans in small hepatocellular carcinoma (HCC) (less than 5 cm) was studied in 82 patients. Dynamic scan was also made in 66 of them. Combined unenhanced and enhanced scans detected 87% of the lesions greater than 2 cm, but the detection rate was only 25% for lesions less than 1.5 cm. Diagnostic failure was due to isodensity of the mass and to technical artefacts. Diagnosis of the surrounding capsule and internal septa (partition) and demonstration of the typical pattern of density enhancement by dynamic scan proved useful in differentiating HCC from secondary cancers. On unenhanced CT, the density of the interior was subject to the histological changes of tumour such as bleeding, necrosis and fatty metamorphosis. Similarly, enhanced CT showed density changes suggestive of these histological changes. Dynamic scan proved particularly useful for lesions less than 3 cm because the typical density enhancement was frequently demonstrated in the arterial phase. It was concluded that unenhanced CT combined with dynamic scan has a high diagnostic value in small HCC and reflects histological changes.

Diagnosis and clinical features of small hepatocellular carcinoma with emphasis on the utility of real-time ultrasonography. A study in 51 patients.

The clinical features and usefulness of various methods for diagnosis of small hepatocellular carcinoma, no greater than 5 cm in diameter, were studied in 51 patients. The diagnosis was verified in 28 patients by hepatic resection and in 4 patients at autopsy. The tumor was less than 3 cm in diameter in 23 patients. In 37 patients (72.5%), the tumor was first discovered by real-time linear scan ultrasonography, generally during a routine periodic follow-up examination of patients with chronic liver disease, mostly cirrhosis. Clinically, 62.7% of the patients were asymptomatic, and symptoms in the remainder were not suggestive of carcinoma. Most patients showed only mildly abnormal liver function tests that did not suggest the diagnosis. Serum alpha-fetoprotein level was normal in 25.5%, and it was elevated above 200 ng/ml in only 33.3%. Among the various imaging modalities, ultrasonography had the highest detection rate (92.2%) for these small hepatocellular carcinomas compared with computed tomography (73.2%), scintigraphy (50.0%), and angiography (86.0%). False-positive lesions, however, were also found frequently by ultrasonography, requiring ultrasonography-guided biopsy for differential diagnosis in some of the patients. Routine examination at regular intervals of patients with chronic liver disease using a combination of real-time ultrasonography and alpha-fetoprotein measurement is currently the most effective approach to detecting small hepatocellular carcinoma.