The most characteristic anatomical feature of simple ulcer of the stomach is the appearance of the edges and of the floor of the ulcer. The edges of recently-formed ulcers (acute ulcers) are clean-cut, smooth, and not swollen. To use Rokitansky's well-known comparison, the hole in the mucous coat looks as if it had been punched out by an instrument. The floor of the ulcer may be smooth and firm or soft and pulpy. The floor and edges of fresh ulcers are often infiltrated with blood, but they may be of a pale-grayish color. Usually no granulations and no pus are to be seen on the surface of the ulcer.70 In ulcers of longer duration the margins become thickened, indurated, and abrupt; the floor acquires a dense fibrous structure.
70 In rare instances granulations may be present, as in a case of W. Müller's, in which their presence rendered difficult the diagnosis of simple ulcer from carcinoma (Jenaische Zeitschrift, v., 1870). The microscope may also be required to distinguish the irregularly thickened margins of old ulcers from scirrhous cancer.
The floor of the ulcer may be the submucous, the muscular, or the serous coat, or, if the whole thickness of the stomach be perforated, it may be some adjacent organ to which the stomach has become adherent, this organ being usually the pancreas or the left lobe of the liver or neighboring lymphatic glands.
The microscopic examination of recently-formed ulcers shows that the tissue immediately surrounding the ulcer is composed of granular material, disintegrated red blood-corpuscles, pale and swollen fragments of connective-tissue fibres, and cells unaffected by nuclear-staining dyes. The red blood-corpuscles are sometimes broken into fragments of various sizes in about the same way as by the action of heat. The gastric tubules are separated from each other and compressed by infiltrated blood, and contain cells which do not stain. Around this margin of molecular disintegration, which has evidently been produced by the action of the gastric juice, there is often, although not constantly, a zone of infiltration with small round cells, probably emigrated white blood-corpuscles. These cells are most abundant near the muscularis mucosæ and in the submucosa. Extravasated red blood-corpuscles extend a variable distance around the ulcer, farthest as a rule in the submucous coat. Many of the blood-vessels in the immediate neighborhood of the ulcer appear normal; others, particularly the arterioles and the capillaries, may be filled with hyaline thrombi. Clumps of hyaline material may also be seen in the meshes of the tissue around the ulcer. Fine fatty granules may be seen in the tissue near the ulcer. The interstices of the loose submucous tissue and the lymphatic vessels are often filled with fibrillated fibrin and scattered blood-corpuscles for a considerable distance around the ulcer.
In the margins of old gastric ulcers there is also a zone of molecular necrosis. The induration and the thickening of the edges of these ulcers are caused by a new growth of fibrillated connective tissue, which blends together all of the coats invaded by the ulcer. This new tissue is usually rich in lymphoid cells, which are often most abundant in the lymphatic channels. In the fibrous edges and base of old ulcers are arteries which are the seat of an obliterating endarteritis, and which may be completely obliterated by this process. An interstitial neuritis may affect the nerve-trunks involved in the fibrous growth. Blood-pigment may be present as an evidence of an old hemorrhagic infiltration.71
71 The histological changes here described are based upon the examination of typical specimens both of recent and of old gastric ulcers which have come under my observation.
Cicatrization is accomplished by the development of fibrous tissue in the floor and borders of the ulcer. By the contraction of this new-formed tissue the edges of the mucous membrane are united to the floor of the ulcer, and may be drawn together so as to close completely the defect in the mucous membrane. The result is a white stellate cicatrix, which is usually somewhat depressed and surrounded by puckered mucous membrane. It is probable that small, superficial ulcers may be closed so that the scar cannot be detected. The mucous membrane which has been drawn over the cicatrix is intimately blended with the fibrous substratum, and is usually itself invaded by fibrous tissue which compresses and distorts the gastric tubules. Hauser72 has shown that the tubular glands grow down into the cicatricial tissue, where they may branch in all directions. These new-formed tubules are lined by clear cylindrical or cutical epithelial cells, and may undergo cystic dilatation. Very irregular cicatrices may result from the healing of large and irregular ulcers. When the ulcer is large and deep and the stomach is adherent to surrounding parts, the edges of the mucous membrane making the border of the ulcer cannot be united by the contraction of the fibrous tissue in the floor of the ulcer. The cicatrix of such ulcers consists of fibrous tissue uncovered by mucous membrane. The closure of the ulcer is incomplete. Such cicatrices are liable to be the seat of renewed ulceration.
72 Das chronische Magengeschwür, etc., Leipzig, 1883. In the rare instances of carcinoma developing in the borders or in the cicatrix of gastric ulcer, Hauser believes that the cancerous growth starts from these glandular growths, which in general have only the significance of Friedländer's atypical proliferation of epithelial cells.
The formation and contraction of the cicatrix may cause various deformities of the stomach. The character of these deformities depends upon the situation, the size, and the depth of the ulcer which is cicatrized. Among the most important of these distortions are stenosis of the pyloric orifice, followed by dilatation of the stomach, more rarely stenosis of the cardiac orifice, with contraction of the stomach, approximation of the cardiac and of the pyloric orifices by the healing of ulcers on the lesser curvature, and an hour-glass form of the stomach, produced by the cicatrization of girdle ulcers or of a series of ulcers extending around the stomach. These abnormalities in form of the stomach, particularly the constriction of the orifices, may be attended by more serious symptoms than the original ulcer.
As the ulcer extends in depth a circumscribed peritonitis, resulting in the formation of adhesions between the stomach and surrounding parts, is usually excited before the serous coat is perforated, so that the gravest of all possible accidents in the course of gastric ulcer—namely, perforation into the peritoneal sac—is permanently or temporarily averted. It has been estimated that adhesions form in about two-fifths of all cases of gastric ulcer (Jaksch). On account of the usual position of the ulcer on the lesser curvature or on the posterior wall of the stomach, the adhesions are most frequently with the pancreas (in about one-half of all cases of adhesion); next in frequency with the left lobe of the liver; rarely with other parts, such as the lymphatic glands, the diaphragm, the spleen, the kidney, the suprarenal capsule, the omentum, the colon, and other parts of the intestine, the gall-bladder, the sternum, and the anterior abdominal wall. Adhesions cannot readily form between the anterior surface of the stomach and the anterior abdominal wall, on account of the constant movement of these parts, so that ulcers of the anterior gastric wall are those most liable to perforate into the peritoneal cavity.