Table 3. . Findings at the microscope.

β-HCA/β-IHCA	Strong/diffuse (or patchy) GS-positive immunostaining and aberrant expression of β-catenin (can be very focal or absent)
Clinical background	HCC in a context strongly suggestive of HCA
Cellular and architectural atypia	Few foci of anisocaryosis or of smaller hepatocytes, thicker hepatocytic plates, decreased reticulin network, some pseudogland formations, cholestasis. Do not forget pitfall: vicinity of bleeding!
Borderline HCA	Well-differentiated hepatocellular neoplasm: several foci of either atypia, rosettes, loss of reticulin, increased CD34 … but insufficient for a straightforward diagnosis of HCC
HCC within HCA	One focus or several foci of HCC within an HCA, or rim of HCA surrounding HCC

GS: Glutamine synthetase; HCA: Hepatocellular adenoma; HCC: Hepatocellular carcinoma; IHCA: Inflammatory hepatocellular adenoma.