Evaluation of malignancy of hepatocellular carcinoma using the ultrasonic B-mode method: clinical significance of extracapsular invasion of hepatocellular carcinoma using ultrasonography.

Purpose: To determine the influence of capsule formation or presence of capsular invasion on the prognosis of hepatocellular carcinoma (HCC) patients.

Methods: The patient group consisted of 70 patients with 74 HCC lesions who had been examined by US and undergone surgical tumor resection at our institution. For these patients, we conducted the following comparative studies: (a) comparison between halo findings on US and microscopic capsular results; (b) comparison between halo findings on US and tumor diameter, tumor histological differentiation, and serum value of each tumor marker; and (c) comparison between halo findings on US and tumor recurrence.

Results: (a) The corresponding value between sonographic halo and histological capsule was 90.1%, and that between presence of extracapsular invasion on US and that seen by histology was 88.0%. (b) There was no relation between US images and histological differentiation of tumors. (c) Presence of extracapsular invasion on US was a predisposing factor for the development of tumor recurrence.

Conclusion: (1) Globally speaking, sonographic halo corresponded to the histological tumor capsule. (2) In patients with extracapsular invasion, tumor recurrence after treatment increased. Thus, a better understanding of sonographic halo findings helps determine diagnostic and therapeutic strategies in HCC patients.