Acute necrotizing pancreatitis — histological study focusing on necrosis and apoptosis

Full text

Acute necrotizing pancreatitis is histologically studied focusing on the degree and extent of necrosis and apoptosis.

Materials and methods

Evaluation was done by light-microscopic examination (Hematoxylin-Eosin stain) and electron-microscopic examination. In order to judge the existence of apoptosis, the TUNEL method was applied.

Only exocrine tissue was surveyed. The number of specimens is three, which were obtained by distal pancreatectomy in the early phase of acute necrotizing pancreatitis because they resisted intensive care. The normal control was one specimen in which 1) negative control and; 2) positive control (TACS-Nuclease-treated control) were used.

Results

Pancreatic tissue was divided into three areas by light- and electron- microscopy before TUNEL: 1) microscopically normal tissue; 2) microscopically apparently necrotized area; 3) minimal or almost normal tissue by the light microscope, although electron-microscopically mild or moderate destructive change of the cytoplasm and nuclear structure was apparent. The TUNEL method revealed the existence of apoptosis in both the the necrotized area (2) and in the minimally destroyed area light-microscopically (3).

Discussion and conclusions

From our study, the existence of apoptosis in acute necrotizing pancreatitis is thought to exist. Several important themes seem to be pointed out: 1) new classification of acute pancreatitis, including apoptosis may be necessary; 2) apoptosis will influence the prognosis or mortality of necrotizing pancreatitis, hitherto believed to depend on the ratio of necrosis; 3) the criteria of severity should be revised.