Liver biopsy features of acute hepatitis C compared with hepatitis A, B, and non‐A, non‐B, non‐C

— The diagnosis of acute hepatitis C (AHC) often can only be suspected because current serologic tests remain negative for over 3 months. Because histologic features might provide useful clues, we reviewed 85 liver biopsy specimens from 85 patients with acute viral hepatitis, comparing 22 cases of AHC with 23 cases of acute hepatitis A (AHA), 30 cases of acute hepatitis B (AHB), and 10 cases of acute hepatitis non-A, non-B, non-C (AHNC). AHC was characterized by dense portal lymphoid aggregates (7 cases) and Poulsen-Christoffersen-type cholangitis (8 cases); these lesions were not found in any other type of acute viral hepatitis, and thus appeared to be diagnostic. Sinusoidal inflammatory infiltrates also were common in AHC, particularly in biopsy specimens obtained during the early phase of the disease. These inflammatory infiltrates did not appear to affect adjacent hepatocytes. Necrosis in AHC usually was spotty and accompanied by mixed inflammatory cells. In AHNC, necrosis was also spotty but, as an added feature, pigmented macrophages predominated in them. In AHA, necrosis was predominantly periportal, whereas in AHB, severe zone-3 necrosis predominated. Fatty changes were predominantly microvesicular; they were common in AHC but were also found in other groups. Collectively, the described histologic features allowed diagnosis of AHC in biopsy specimens with reasonable confidence. However, histologic findings failed to predict the prognosis in individual cases.