Significance of presence of microvascular invasion in specimens obtained after surgical treatment of hepatocellular carcinoma.

Partial hepatectomy and liver transplantation are potentially curative treatments in selected patients with hepatocellular carcinoma (HCC). Unfortunately, a high postoperative tumor recurrence rate significantly decreases long-term survival outcomes. Among multiple prognostic factors, the presence of microvascular invasion (MVI) has increasingly been recognized to reflect enhanced abilities of local invasion and distant metastasis of HCC. Unfortunately, MVI can only currently be identified through histopathological studies on resected surgical specimens. Accurate preoperative tests to predict the presence of MVI are urgently needed. This paper reviews the current studies on incidence, pathological diagnosis, and classification of MVI; possible mechanisms of MVI formation; and preoperative prediction of the presence of MVI. Furthermore, focusing on how the postoperative management can be improved on histopathologically confirmed patients with HCC with MVI, and the potential roles of using predictive tests to estimate the risk of presence of MVI, helps in preoperative therapeutic decision-making in patients with HCC.