Diagnostic accuracy of thick needle biopsy under intraoperative ultrasound guidance for the small nodule in the liver associated with hepatocellular carcinoma

Intraoperative ultrasound found many new small nodules in the liver other than the main lesion which had detected preoperatively. Ultrasound cannot diagnose the histological nature of these nodules moreover, accuracy of five needle aspiration cytology for these nodules was only 45 percent. Therefore, we have changed our policy to thick needle biopsy with a 14 gauge Tru-Cut needle. A total of 35 needle biopsies for small nodules in the liver under intraoperative ultrasound guide was performed on 31 patients with hepatocellular carcinoma. Histological diagnosis of frozen section of the core biopsy were compared with the resected specimens and the clinical results of follow up for more than one year. Sensitivity, positive and negative predictive value and overall accuracy of histological diagnosis by frozen section were 46.7, 100, 100, 71.4 and 77.1 percent respectively. When diagnosis of frozen section was adenomatous hyperplasia, 50 percent of them was malignant. Because well differentiated hepatocellular crcinoma and adenomatous hyperplasia are difficult to differentiate even with paraffin section of the resected specimen, these nodules would be better to resect as far as liver function permits.