This section is from the book "A Manual Of Pathology", by Guthrie McConnell. Also available from Amazon: A Manual Of Pathology.
The connective-tissue tumors, as fibroma, myoma, and lipoma, have been occasionally found. Sarcoma is more rare; it seems to originate within the lymphoid deposits and is generally round-cell in character. Polypoid projections of the mucous membrane are sometimes confused with tumors, but they are not neoplastic, are the result of chronic inflammations, and are sometimes cystic.
Adenomas have been found, but they are unusual, as they generally very quickly undergo a carcinomatous degeneration.
Carcinoma is quite common and is nearly always primary. It is more frequent in men than in women, usually in middle or advanced life. Its most frequent seat is at the pyloric end of the stomach, on the posterior wall of the lesser curvature. It sometimes first appears at the cardiac end. The walls may be more or less involved in the process. The appearance of the growth differs greatly according to its histologic characteristics.
Scirrhns Cancer is usually situated at the pyloric opening, which may be completely or partially surrounded. The walls are thickened and indurated. The opening is much stenosed and the mucous surface may be smooth or irregular with depressed and ulcerated areas. Microscopically there will be seen large amounts of dense connective tissue with a few atypical epithelial cells. Is less actively metastatic than the other forms.
In these cases the stomach may be much enlarged.
Medullary Carcinoma generally appears at the pylorus, but sometimes on the wall in the lesser curvature. The growth is irregularly elevated, spongy, and cauliflower-like. Is soft and vascular and ulcerated, particularly in the center, thus forming a crater-like excavation where perforation may occur. Microscopically the epithelium predominates and retains to some extent the normal arrangement, although the individual cells rapidly become more globular and less columnar. Is actively metastatic.
Malignant Adenoma or adenocarcinoma begins as a proliferation of the glandular tubules. The cells retain to a great extent their usual shape and regular arrangement. Further away from the original focus the glandular conformation becomes less and less marked, until it may completely disappear and be replaced by the usual carcinomatous picture.
Colloid Cancer may be localized or, what is more common, diffuse. The mucosa and submucosa may be markedly infiltrated and the surface covered by a gelatinous material. This is better seen deeper in the tissues, as that exposed is dissolved by the gastric juices. On section a yellowish gelatinous material escapes. The cells are cylindric and there is a myxomatous degeneration of them and of the intercellular elements.
Fig. 150. - Scirrhus of the Pylorus, Causing Pyloric Stenosis (Orth). D, Duodenum; P, pylorus; K, carcinomatous projections on the mucosa.
Squamous epithelioma occurs at the cardiac end of the stomach as an extensiou from a growth primary within the esophagus. Is very rare.
The involvement generally takes place within the gastric tubules. This is soon followed by an infiltration of the submucosa, the muscularis, and finally the serous covering, upon which there appear nodules. Perforation of the wall may then occur with subsequent involvement of the peritoneum; this is especially so in colloid cancer. Neighboring organs, as the liver, pancreas, and colon, may be affected by contiguity. If adhesions have formed perforation may be prevented and the neighboring tissues protected. Fistulous tracts may be opened between the stomach and duodenum or transverse colon, or with the pleura. Metastases may take place first in the neighboring lymphatics and then in more distant tissue, or secondary nodules may follow the entrance of tumor cells into veins. These are commonly carried to the liver, where they lodge and grow. The metastatic growths may be so large as to conceal the primary neoplasm. If at the pylorus there will be all the symptoms of obstruction, such as retention of food with decomposition.
Lactic acid fermentation is particularly common, as there is generally a lack of hydrochloric acid secretion. The stomach may become enormously dilated.
Following the ulcerative processes there may be extensive hemorrhage from the opening of a blood-vessel or there may be merely an oozing with the presence of the "coffee grounds" vomit.
Foreign bodies of many kinds may be found, either accidentally or intentionally swallowed. Intestinal parasites may also be present.