Histological Typing of Oesophageal and Gastric Tumours

This classification is based primarily on the microscopic characteris- tics of tumours. It is therefore concemed with the identification of cell types and histological pattems as seen by conventional light mi- croscopy. In general, time-honoured terms have been retained. Syn- onyms are listed only if they have been widely used, or if they are considered 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 the tumour manifests itself principally in its histological appearance and the extent of spread at the time of diag- nosis. This volume is concemed only with the histological classifica- tion of tumours. Anatomieal extent or staging is covered in the TNM 1 Classification. The histological classification of a tumour depends on two main parameters, typing and grading, and a number of additional parame- ters which may apply to selected examples.