**1. Introduction**

The pathologist who deals with gastric tumours is responsible for the determination of the following factors:


Adenocarcinoma (including different subtypes) is the most common malignant gastric tumours of epithelial origin. In Western countries, declining incidence of gastric carcinoma is found; nevertheless, it remains the second most common cause of cancer-related death in the world [3]. In Germany, we expect about 9200 men and 6400 women with a newly diagnosed gastric carcinoma per year, and 70% of them will die carcinoma-related in the following 5

**Figure 1.** Pathogenesis of intestinal-type gastric adenocarcinoma.

years. Particularly, if metastases/recurrences occur, the prognosis is still dismal with a median survival of 8 months (krebsdaten.de—Robert-Koch-Institut, Berlin 2015). Particularly, in Northern Europe and the United States, the distribution of carcinomas within the stomach changed in the past decades. The distal-located tumours (typically from the diffuse type of adenocarcinoma) are decreasing and the proximal tumours (typically from the intestinal type of adenocarcinoma) are increasing [1, 2].

From the pathophysiological point of view, main features of the intestinal type of gastric adenocarcinoma are (a) chronic inflammation of the mucosa (typically due to an infection of helicobacter pylori) with related mucosa damage and atrophy, (b) intraepithelial neoplasia and (c) fully invasive adenocarcinoma (**Figure 1**).
