[Diagnosis of seronegative chronic hepatitis in tissue]. / Diagnostik der "seronegativen" chronischen Hepatitis am Gewebe.

The evaluation of a liver biopsy in chronic hepatitis should make a statement on the etiology and report the degree of activity and stage of the disease. The category of so called seronegative chronic hepatitis may include cases of chronic hepatitis C or infection with other viruses such as the Epstein-Barr virus (EBV) and cytomegalovirus (CMV), cases of marker-negative autoimmune hepatitis as well as drug-induced injury and Wilson's disease in younger patients. In order to establish the diagnosis, sensitive techniques of molecular biology should be applied as well as copper staining by histochemistry. Exact and detailed histopathologic analysis can reveal certain features of autoimmune hepatitis or drug injury.

[Highly differentiated hepatocellular tumors. Concepts, criteria, and differential diagnosis]. / Hochdifferenzierte hepatozelluläre Tumoren. Konzepte, Kriterien und Differenzialdiagnose.

Well-differentiated hepatocellular tumors represent a difficult diagnostic problem in hepatopathology with rising clinical impact. The differential diagnosis mainly includes well-differentiated hepatocellular carcinoma (HCC) and its premalignant precursor lesion, the dysplastic nodule (DN), in addition to multiacinar regenerative nodule as well as hepatocellular adenoma (LCA) and focal nodular hyperplasia (FNH). Optimized diagnosis of these lesions is based on exact histomorphological analysis, a close interdisciplinary cooperation as well as good clinical and anamnestic information. Histopathological differential diagnosis requires the search for specific characteristics and detailed analyses of the subtle cytological differences, the histoarchitecture, and also the surrounding nontumorous liver tissue. Special techniques may be helpful in selected cases but currently are of limited importance.