Piecemeal necrosis

Piecemeal necrosis This is the fundamental element of a progressive, chronic-inflammatory process. The necrosis is brought about by cytotoxic T lymphocytes, which may be located within a recess of the hepatocyte (=... 

In persistent confluent and bridging necrosis, the development of correspondingly located fibrotic septa can be observed. Portoportal septa connect neighbouring portal tracts, such as in progressive piecemeal necrosis and in... 

The transformation of the lobular architecture is initiated and maintained by at least two histomorphological processes (i.) piecemeal necrosis and (2.) bridging necrosis, which provides string-like links between the central veins and the portal fields. Portocentral shunts, which are of significance for the fate of cirrhosis, make use of these bridges as routes for their development. During the course of time, these channels, which acquire solid basal membranes like capillaries, carry the portal blood directly to the venous flow-off. As a result, blood is withdrawn from the respective acini these areas become more susceptible to disruption and damage and are forced to restructure anew, (see chapter 35)... 

Stage II The periportal stage presents an encroachment of the inflammatory changes on the parenchyma with piecemeal necrosis connective tissue proliferations also break into the lobule (so-called periportal hepatitis + fibrosis). Liver cell necroses are also found sporadically, whereby CD4 cells, CD56-NK cells and lymphocytes are markedly increased. In places, reduction in and fibrosis of bile ducts are already in evidence, (s. fig. 32.13) (335, 349, 384)... 

The cause of autoimmune hepatitis (AIH) is unknown. Autoimmune reactions lead to a chronic (rarely acute) inflammatory process (periportal piecemeal necrosis, infiltration of portal zones). AIH is frequently associated with autoimmune diseases of other organs. It occurs predominantly among women, particularly in younger years. Hypergammaglobulinaemia is invariably in evidence. Various autoantibodies to components of the liver parenchyma are found. The presence and specificity of these antibodies, together with the respective clinical symptoms, facilitate differentiation between the various subtypes of AIH. Diagnosis is substantiated by the response to immunosuppressive therapy. If left untreated, AIH progresses rapidly with transition to cirrhosis and/or liver failure. If treated adequately, the course taken by the disease is favourable. 

Periportal inflammation Periportal hepatitis is characterized by penetration of the limiting plate. The border between the portal field and the lobule can appear irregular sometimes it assumes the shape of a maple leaf In this periportal zone (i.e. zone 1), piecemeal necroses may develop. They are, however, not true necroses , but apoptoses. Today, periportal inflammation with piecemeal necrosis is termed interface hepatitis. This condition is not always accompanied by piecemeal necrosis the inflammatory infiltrate can also enter the lobule without causing liver cell necroses. The composition of the inflammatory infiltrates is similar to that in the portal fields. Periportal infiammation contributes to the grading of chronic hepatitis, (l)... 

Fig. 34.4 Chronic active hepatitis with periportal piecemeal necrosis (—>) and apoptosis ( ) in the lobular parench)ma...

Kerr JFR, Searle J, Halliday WJ, Roberts I, Cooksley WGE, Halliday JW, Holder L, Burnett W, Powell LW (1979) The nature of piecemeal necrosis in chronic active hepatitis. Lancet 2 827-828... 

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