Management of new hepatic nodules detected by intraoperative ultrasonography during hepatic resection for hepatocellular carcinoma

Background. During hepatic resection for hepatocellular carcinomas (HCCs) it is not uncommon that intraoperative ultrasonography detects ''new nodules'' that were not found by preoperative examinations. Because the operative procedure may have to be changed if the new nodule is another HCC lesion, differential diagnosis of such nodule is critical. This study examines ultrasonographic findings and clinical features of new nodules an discusses how to cope with such nodules in the operating room. Methods. Fifty-one nodules detected in 92 liver resections were analyzed. Intraoperative ultrasonography was performed by using 5.0 or 7.5 MHz probes after mobilization of the liver. Histologic diagnosis of the new nodules was made by means of enucleation, resection with the primary lesions, thick-needle biopsy, or additional partial resection of the liver. Results. New nodules were detected in 27 (29.3%) of 92 resected cases. Internal echoic pattern of the nodules were type I, hypoechoic (29 nodules); type II, hyperechoic (19); and type III, mosaic (3). Ten HCC nodules (17.9%) were included, and chance of being malignant new nodules, three underwent additional systematic resection and all were alive without recurrence 49, 13, and 11 months after the operation. Others were treated by use of enucleation (two cases), intraoperative ethanol injection (one case), and intraarterial chemotherapy (one case). Conclusions. Although most of the new nodules specific findings for HCC, hypoechoic nodules, 24.1% of which were HCCs, should not be overlooked. Histologic confirmation of the new nodules is necessary especially when the number of lesions detected before operation is multiple or the interval between lipiodol computed tomography and the operation is longer than 2 months. Once the diagnosis of HCC has been made for the new nodule, systematic additional resection to remove the new lesion is recommended.