Development of hepatocellular carcinomas in patients with absence of tumors on a prior ultrasound examination

Background: To evaluate hepatocellular carcinoma (HCC) that developed in patients with no evidence of a tumor during a prior ultrasound (US) performed within 1 year of the diagnosis. Methods: We retrospectively analyzed data for 100 consecutive patients with liver cirrhosis who had undergone US within 1 year prior to HCC diagnosis and who showed no liver lesions on the previous US. Size and T stage of HCC were assessed as well as whether patients met surgical criteria for liver transplantation as HCC treatment [Milan or University of California at San Francisco (UCSF) criteria]. Results: The mean interval between the negative and diagnostic scans was 5 months, 13 days. HCC presented as a single nodule in 69 patients (size, 0.8–8.0 cm), as two or more nodules in 18 patients, and as the diffuse form of HCC in 13 patients. HCC presented as a small tumor (<3 cm) in 48 patients. T stages were: T1 in 26 patients, T2 in 45, T3 in 18, and T4 in 11. The Milan criteria were met in 79 patients. Eighty-five patients fulfilled the UCSF. Conclusion: Patients may present with advanced HCC, even if sonographic findings were negative within 1 year prior to diagnosis.