Tumors of the stomach can either be benign (non-cancerous) or malignant (cancerous). There are certain tumors that are classified as atypical (uncertain or unspecified behavior) meaning that some behave in a benign manner, or some behave in a malignant manner. A majority of the gastric tumors diagnosed via lab studies (biopsy) are benign.

The World Health Organization (WHO) is an authoritative body that compiles, prepares, and publishes histological and molecular classification of tumors, via their Blue Books, based on research inputs from experts worldwide. These reference books chiefly aid in global cancer research, provide gold standards for tumor diagnosis, and help in treating cancer patients.

According to the WHO Classification of Digestive System Tumors (2019), 5th Ed., Vol. 1, benign and malignant tumors of the stomach are classified in the following manner:

Tumors of the stomach:

Tumors of the stomach

Gastritis and metaplasia: precursors of gastric neoplasms

Epithelial tumors

• Benign epithelial tumors and precursors
  • Fundic gland polyps
  • Gastric hyperplastic polyps
  • Gastric dysplasia
  • Intestinal-type gastric adenoma
  • Foveolar-type adenoma
  • Gastric pyloric gland adenoma
  • Oxyntic gland adenoma
• Malignant epithelial tumors
  • Gastric adenocarcinoma
  • Gastric squamous cell carcinoma: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old
  • Gastric adenosquamous carcinoma: It is a very rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old
  • Gastric undifferentiated carcinoma: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old
  • Gastroblastoma
  • Gastric neuroendocrine neoplasms

Additional stomach tumor articles (on DoveMed) that are not part of WHO Classification of Digestive System Tumors:

Angiomyolipoma of Stomach: It is a very uncommon extrarenal angiomyolipoma that may be present in the stomach. It is observed in both men and women.

Carcinoma with Lymphoid Stroma of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old..

Carcinosarcoma of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Choriocarcinoma of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Diffuse Large B-Cell Lymphoma (DLBCL) of Stomach: It is a rare, B-cell non-Hodgkin’s lymphoma that affects older adults.

Diffuse Type Gastric Carcinoma: It is a form of gastric carcinoma that is diagnosed under a microscope, on examination of the cancer cells by a pathologist. It may occur in both men and women.

Embryonal Carcinoma of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer.

Endodermal Sinus Tumor of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Gastric Carcinoma: It is a type of stomach cancer that is commonly observed around the world, in both men and women.

Gastric Duplication Cyst: It is a rare congenital malformation that is characterized by the presence of a cyst in the stomach. The presentation of symptoms may occur at birth.

Gastric MALT Lymphoma: It is a slow-growing B-cell non-Hodgkin’s lymphoma affecting adults. It is termed marginal zone lymphoma of the stomach.

Gastrointestinal Stromal Tumor of Stomach: It is a common tumor that forms anywhere in the stomach. The tumor is mostly observed in older adults.

Glomus Tumor of Stomach: It is a very rare tumor that is mostly benign. A glomus tumor is seen among a wide age range of adults and can occur at various body sites.

Hemangioma of Stomach: It is a very rare benign vascular tumor that forms in the stomach. It is mostly observed in both men and women.

Hepatoid Adenocarcinoma of Stomach (HAS): It is a very rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Inflammatory Myofibroblastic Tumor of Stomach: It is a rare and mostly benign tumor that can occur anywhere in the stomach. The tumor generally occur in younger populations and can grow to large sizes.

Intestinal Type Gastric Carcinoma: It is a form of gastric carcinoma that is diagnosed under a microscope, on examination of the cancer cells by a pathologist.

Kaposi Sarcoma of Stomach: It is a rare high-grade malignancy that is seen in the stomach, mainly against a background of AIDS/HIV-infection.

Leiomyoma of Stomach: It is a very rare benign tumor that forms in the stomach. Leiomyomas arise from smooth muscles and may develop in both children and adults.

Leiomyosarcoma of Stomach: It is a very uncommon and highly-malignant mesenchymal (non-epithelial) tumor. is observed in adults. It is generally seen in adults over 30 years old.

Lymphoma of Stomach: It is an uncommon lymphoma that is mostly observed in older adults. It is also known as Gastric Lymphoma.

Malignant Rhabdoid Tumor of Stomach: It is a very rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Mantle Cell Lymphoma of Stomach: It is an extremely rare and aggressive B-cell non-Hodgkin’s lymphoma typically affecting older adults.

Mixed Adenocarcinoma of Stomach: It is a histological variant and aggressive form of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Mucinous Adenocarcinoma of Stomach: It is a histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Mucoepidermoid Carcinoma (MEC) of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Oncocytic Adenocarcinoma of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Paneth Cell Carcinoma of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Papillary Adenocarcinoma of Stomach: It is a histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Parietal Cell Carcinoma of Stomach: It is a rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Plexiform Fibromyxoma of Stomach: It is a highly-uncommon benign tumor of the stomach. It is present in both children and adults.

Poorly-Cohesive Carcinoma of Stomach: It is a histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Pure Gastric Yolk-Sac Tumor (YST): It is a very rare histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Schwannoma of Stomach: It is an extremely rare and a mostly benign tumor that arise from the Schwann cells around the nerves. It is usually seen in elderly adults.

Signet-Ring Cell Carcinoma (SRCC) of Stomach: It is a histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.

Synovial Sarcoma of Stomach: It is an extremely uncommon and malignant mesenchymal (non-epithelial) tumor. It is observed in children, teens, and young and middle-aged adults

Tubular Adenocarcinoma of Stomach: It is a histological variant of gastric carcinoma, which is a type of common stomach cancer. It is generally seen in adults over 30 years old.