We read with great interest the article by Iavarone et al.,1 who studied the role of tumor grading in the diagnosis of hepatocellular carcinoma (HCC) detected during surveillance by dynamic contrast imaging techniques in patients with compensated cirrhosis. The authors showed that the tumor grade and size influence the accuracy of imaging techniques in HCC diagnosis; in fact, accuracy was greater for poorly differentiated (high-grade) nodules > 2 cm versus more differentiated (low-grade) nodules ≤ 2 cm. These observations indirectly confirm the correlation between HCC grade and vascularization: high-grade HCC is better detected by imaging.2, 3
We appreciate the attempt of Iavarone et al.1 to find a correlation between diagnostic imaging techniques and HCC grading because the latter greatly influences HCC outcomes and is a strong predictor of recurrence after surgery.
However, we believe that the only way to obtain preoperative histological information is needle core biopsy (NCB). We recently evaluated the overall accuracy of preoperative NCB in assessing tumor grading in patients with cirrhosis undergoing liver resection for a single HCC.4 We found that preoperative NCB is a safe procedure (no serious adverse events were observed) and an accurate tool for assessing the tumor grade, particularly for small HCCs. In fact, for HCCs < 3 cm, we found an accuracy of 97%, a sensitivity of 86%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 96%, whereas for HCCs < 2 cm, we found an accuracy of 93%, a sensitivity of 100%, a specificity of 75%, a positive predictive value of 91%, and a negative predictive value of 100%. The overall accuracy in detecting low-grade HCCs was greater than the overall accuracy in detecting high-grade HCCs (98% versus 65%, respectively). NCB is the only technique also capable of grading small HCCs (≤2 cm); dynamic contrast imaging techniques have poorer diagnostic accuracy. Moreover, we did not observe any correlation between tumor size and HCC grading; this observation was also made by Iavarone et al.1 In fact, we found that high-grade HCCs were present to the same extent (ca. 20%) in nodules ≤ 3 cm and in nodules > 3 cm.
All these findings, together with the inconsistent recent results regarding the contrast enhancement ultrasonographic pattern as a predictor of HCC grading,5, 6 underscore and elevate the importance of the role of preoperative NCB. However, we believe that NCB should be performed not only for small nodules present in patients with cirrhosis, which could be undetected by imaging techniques, but also for those nodules detected by imaging and those nodules in the surrounding liver tissue. Preoperative histological information (mainly HCC grading) and genetic profiling7 represent essential tools for updated HCC clinical management.