(1) The Esophagus

Stricture of the cardiac orifice is usually attended by slight dilatation of the lower third of the oesophagus and hypertrophy of its muscular coat. Invasion by the malignant growth occurs in "about 46 per cent, of the cases of primary carcinoma in the cardiac half of the stomach, and not infrequently leads to perforation of the tube, with secondary inflammation of the left pleura or lung. Towards the end of life thrush is apt to extend downwards from the pharynx, and occasionally enlargement of the solitary glands or follicular ulceration is observed just above the cardiac orifice.

(2) Stomach

Chronic gastritis almost invariably accompanies carcinoma of the stomach. At an early stage of the disease two varieties may be distinguished-the parenchymatous and the interstitial; but at a later period they usually coexist.

Chronic Parenchymatous Gastritis is most common in cases of soft spheroidal-celled and cylinder-celled growths of the body of the organ. To the naked eye the mucous membrane appears soft, swollen, and opaque, or exhibits a patchy form of congestion. On microscopical examination the superficial epithelium is found to be partially detached, and many of its cells are seen to be distended with mucus. The ducts of the glands are filled with granular and -fatty cells of various sizes and shapes, with a few red blood-corpuscles and a considerable quantity of debris. The glands themselves are usually swollen, irregular in outline, and overlap one another. No lumen is visible, and no distinction can be made between central and parietal cells. At some parts of the section the tubules are completely filled with polygonal cells derived from the peptic cells ; at others their contents consist principally of fatty detritus ; while in advanced cases they appear shrivelled and empty and separated from one another by newly formed interstitial connective tissue. The vessels which ramify in the submucosa are dilated and engorged with blood, and there are usually signs of inflammatory exudation around the smaller arterioles on either side of the muscularis mucosae. Occasionally groups or lines of cancer cells may be observed in the lymph spaces, even when the section has been made at some distance from the neoplasm.

Chronic Interstitial Gastritis invariably accompanies obstruction of the pylorus by a carcinomatous growth. In such cases the inner surface of the stomach exhibits after death a thick coating of tenacious mucus, and when this has been removed the mucous membrane presents an appearance of extreme congestion, with here and there a small haemorrhage or a superficial ulcer. When examined by the microscope the section exhibits an irregular or distinctly villous surface, from hypertrophy of the connective tissue between the mouths of the ducts, and is almost denuded of epithelium. The ducts of the glands are twisted and distorted, and their lumina are often choked with mucus, detached cells, and debris. The glands themselves are separated from one another by strands of fibrous tissue, the thickness of which varies in different places. As the disease progresses the peptic cells of the cardiac region undergo secondary changes, which ultimately result in their detachment and disintegration ; but in the pyloric end of the organ the comparatively long and tortuous tubules are not infrequently constricted by the new interstitial tissue. Under these circumstances the lower ends of the glands become dilated and form small cysts, which are lined by cubical epithelium and filled with mucus (retention cysts). Extension of the inflammatory process to the deeper structures destroys the muscularis mucosae and produces partial fibrosis of the submucosa.

The fact that both varieties of inflammation, as well as a similar lesion of the intestine, are met with in cases of scirrhus of the mamma and other chronic carcinomata, renders it probable that they arise from the absorption of some deleterious material produced by the disintegration of the neoplasm, and are therefore allied to other toxaemic inflammations of the digestive tract.

(3) Small Intestine

Invasion of the duodenum by continuity takes place in about 5 per cent, of the cases, but metastases are extremely rare. The jejunum is occasionally involved and its wall destroyed bv a large growth of the pylorus.

(4) Large Intestine

This portion of the intestinal tract is very liable to be attacked by chronic inflammation during the later stages of gastric carcinoma, and occasionally membranous colitis or ulceration is discovered after death. Metastases are chiefly met with in the rectum, but the transverse colon is often involved by a growth of the pylorus or greater curvature.