Pathological types of gastric cancer

Adenocarcinoma accounts for about 95% of gastric cancer. The most commonly used classification of gastric adenocarcinoma is the WHO classification.

1. Tubular adenocarcinoma

Tubular adenocarcinomas have markedly dilated or slit-like and branching ducts with varying luminal sizes and may also have alveolar structures.

2. Papillary adenocarcinoma

Papillary adenocarcinoma has elongated finger-like projections covered with cylindrical or cuboidal epithelium and a core of fibrovascular connective tissue.

3. Mucinous adenocarcinoma

More than 50% of mucinous adenocarcinomas contain extracellular mucus pools, which can have two main growth patterns: one is that the gland is composed of columnar mucus-secreting epithelial cells, and mucus exists in the interstitial cavity; the other is that the cells are scattered in chains or strings and float in the mucus lake.

4. Signet ring cell carcinoma

More than 50% of the cells in signet ring cell carcinoma are composed of isolated or small clusters of malignant cells containing intracellular mucus. There is also a commonly used Lauren classification method, which describes two histological types of gastric cancer, namely intestinal type and diffuse type. The intestinal type mainly evolves from precancerous lesions (mainly including atrophic gastritis and intestinal metaplasia) and is more common in the elderly and men, indicating the main role of environmental factors in the development of gastric cancer. The diffuse type is generally not evolved from precancerous lesions, mainly occurs in areas with low incidence of gastric cancer, is more common in women and young patients, and is related to family factors (such as blood type A). Although the naming of Lauren classification is somewhat confusing, this classification method is helpful for our in-depth understanding of the etiology and epidemiology of gastric cancer.

In addition, although there is no normal lymphoid tissue in the gastric mucosa, the stomach is the most common site for gastrointestinal lymphoma. The close relationship between Helicobacter pylori infection and gastric mucosa-associated lymphoma, which is currently highly valued, can explain this phenomenon. Gastric lymphoma is a disease that is significantly different from gastric adenocarcinoma in terms of staging, treatment, and prognosis. Other types are less common, including leiomyosarcoma, squamous cell carcinoma, adenosquamous carcinoma, carcinoid, etc.