Book 4 - Self Instructional Manual for Cancer Registrars - SEER ...

The functions of the stomach are to:1. Absorb water and glucose into the blood stream.2. Secrete gastric enzymes. For example, rennin to clot milk; iipase to initiate the splitting offats; pepsinogen, which in the presence of hydrochloric acid forms pepsin, to begin proteinbreakdown.3. Secrete hydrochloric acid (Hcl) which kills bacteria, changes some minerals to salts which aresuitable for absorption in the intestine, and adjusts the pH of the chyme to permit the openingof the pyloric sphincter.4. Produce, in the gastric mucosa, the intrinsic factor which is necessary for the absorption ofVitamin B12.5. Secrete, in the pyloric glands, an alkaline mucous to neutralize the HCI.6. Churn the food into a semi-liquid substance (chyme) and force it through the pyloric sphincterinto the duodenum.Malignantand Benign Tumors• Adenocarcinoma is the most frequent malignant lesion of the stomach. The spread of thetumor is usually to regional lymph nodes and the liver. Later metastasis frequently occurs inthe lungs, brain, bone, and ovaries. A tumor known as Krukenberg tumor is found in theovary which represents a metastasis of adenocarcinoma of the gastrointestinal tract, usuallyof the stomach, to the ovary.• Lymphomas arise more frequently in the stomach than in any other extranodal site. Anyhistologic type of lymphoma, including Hodgkin's disease, may occur.° Leiomyosarcoma arises in the smooth muscles of the stomach wall.° Squamous cell carcinoma occurs at the cardioesophageal junction.• Linitis plastica is an advanced form of cancer which is characterized by a thickening of thestomach wall causing it to lose its elasticity and become rigid like a leather bottle. It has,therefore, been referred to as leather-bottle stomach.• Leiomyomas and adenomas are the two most common benign tumors of the stomach.211