Synopses & Reviews
This second edition of the highly successful WHO histological classification of intestinal tumours is the result of an international collaborative effort by pathologists from nine countries. Revision was undertaken where necessary to reflect important changes that have occurred since the first edition in 1976. A bridge between the purely morphological and the immunological classification of the lymphomas is given. The approach to endocrine tumours, based on a combination of routine stains and immunohistochemical methods, supplants the former criteria based on silver stains. Considerable attention is given to the dysplasias, whose relevance in diagnostic pathology has increased with the advent of endoscopy. Several new entities have been added, and the precision of the proven sections has been enhanced. These changes update the classification, which will continue to facilitate data comparison by providing a standardized, international terminology.
Synopsis
This classification is based primarily on the microscopic characteris- tics of tumours. It is therefore concerned with the identification of cell types and histological patterns as seen by conventional light micro- scopy. In general, time-honoured terms have been retained. Syn- onyms are listed only if they have been widely used or if they are con- sidered to be important for understanding the disease process. In such cases, the preferred term is given first, followed by the synonym in parentheses. The individuality of a tumour manifests itself principally in its histological appearance and the extent of spread at the time of diag- nosis. This volume is concerned only with the histological classific- ation of tumours. Anatomical extent or staging is covered in the TNM Classification. The histological classification of a tumour de- pends on two main parameters, typing and grading, and a number of additional parameters which may apply to selected examples. Histological Typing This divides tumours of a given organ into different types according to their direction of differentiation. Although this may frequently in- dicate the underlying histogenesis of the tumour, it may be difficult or impossible to identify the cell of origin. Note is taken of the structure and function of cell types, as well as the overall growth pattern of the tumour, with the aim of matching these features to those of a normal tissue found in the same organ.
Table of Contents
Introduction Histological Classification of Intestinal Tumours Small Intestine Appendix Large Intestine Anal Canal Anal Margin Definitions and Explanatory Notes Small Intestine Appendix Large Intestine Anal Canal Anal Margin Subject Index