**2.2. Classification according to Lauren (established 1965)**

### *2.2.1. Intestinal type*

Cohesive tumour cells form tubular, papillary or solid structures. The tumour typically shows well-demarcated pushing borders and it is associated with chronic gastritis (usually w Hp-infection) including intestinal metaplasia and pre-cancerogenous epithelial lesions like flat intraepithelial neoplasia/dysplasia. Abundant intracytoplasmic mucin production is not a feature.

#### *2.2.2. Diffuse type*

Poorly or non-cohesive tumour cells include signet-ring cells. The tumour typically shows infiltrating margins. Usually intestinal metaplasia of the gastric mucosa or classic dysplasia is absent. Probably a signet-ring cell carcinoma *in situ* develops from the proliferative foveolar zone and directly invades into the lamina propria.

#### *2.2.3. Indeterminate type*

Mix of intestinal type and diffuse type tumour cells.

#### **2.3. Goseki classification (established 1992)**

According to the degree of tubular differentiation and the amount of intracellular mucin, this classification separates four subtypes.

