Definitions and classifications of pancreatitis.

The historical progress of medical knowledge has followed two primary courses. One course has been based mostly on pathology: the description of specific groups of features and of the corresponding causes and symptoms, i.e., the description of different diseases that are progressively distinguished one from another. At the present time, disorders of molecular biology as well as pathological lesions are increasingly playing a role in the definition of diseases. The second course is a preliminary step to the first: when pathological data have not been available, patients have been classified according to symptoms. This does not lead to the description of the diseases but rather of the syndromes. It is puzzling to see that this obsolete method is still commonly used in pancreatology.