1Section of Abdominal Ultrasound, Kobe City General Hospital, 2Division of Gastroenterology, Kobe City General Hospital
Hypoechoic nodules, Adenomatous hyperplasia, Early hepatocellular carcinoma
The outcome of hypoechoic hepatic nodules less than 1.5 cm in diameter was studied with clinical and ultrasonic follow-up carried out over 3 years. The evidence of hepatocellular carcinoma (HCC) was not obtained by angiography, lipiodol CT, or biopsy in these 55 nodules at the time of initial detection. Three years after detection, enlargement of the nodule size was observed in 9 (16%) of the 55 nodules, while the size had not changed in 19 (35%) nodules. Twentyseven (49%) nodules became undetectable with US. Two of the 9 enlarged nod ules were diagnosed as adenomatous hyperplasia and the remaining 7 nodules were diagnosed as HCC at the final diagnosis. HCC was observed to have occurred in a different area from that of the initially detected nodule lesion in patients with 8 of the 19 "unchanged" nodules and 4 of the 27 nodules that disappeared during the three years follow-up. It was concluded that 13% of the hypoechoic nodules less than 1.5 cm and without signs of malignancy develop to HCC, whereas most of those nodules (49%) become undetectable with US, suggesting those are benign nodules.