From this table it is apparent that ulcers occupy the lesser curvature, the posterior wall, and the pyloric region three and a half times more frequently than they do the remaining larger segment of the stomach.
66 These statistics are collected from the previously-cited works of Rokitansky, Jaksch, Wrany, Eppinger, Chambers, Habershon, Steiner, Wollmann, Berthold, Starcke, Lebert, and Moore. They represent 566 cases. So far as noted, most of the ulcers on the posterior wall were nearer to the lesser curvature than to the greater; those on the lesser curvature extended more frequently to the posterior than to the anterior wall. Although not apparent from the table, most of the ulcers of the lesser curvature and of the posterior wall were in the pyloric region. So far as possible, cicatrices were excluded. Pylorus and cardia in the table indicate on or near those parts.
Occasionally two ulcers are seated directly opposite to each other, the one on the anterior, the other on the posterior, wall of the stomach. The most plausible explanation of this is that the ulcers are caused by a simultaneous affection of corresponding branches which are given off symmetrically from the same arterial trunk as it runs along one of the curvatures of the stomach (Virchow).67
67 A. Beer, "Aus dem path. Anatom. Curse et. Prof. R. Virchow, etc.," Wiener med. Wochenschr., Nos. 26, 27, 1857.
The ordinary size of the ulcer varies from a half inch to two inches in diameter. The ulcer may be very minute, as in two cases reported by Murchison, in each of which a pore-like hole was found leading into a perforated artery from which fatal hemorrhage had occurred.68 On the other hand, the ulcer may attain an enormous size, extending sometimes from the cardiac to the pyloric orifice and measuring five or six inches in diameter.69
68 Murchison, Trans. of the Path. Soc., vol. xxi. p. 162, London, 1870.
69 In one of Cruveilhier's cases the ulcer was 6½ inches long and 31/3 inches wide. Law describes an ulcer measuring 6 inches by 3 inches (Dublin Hosp. Gaz., ii. p. 51).
The ulcer is usually round or oval in shape. The outline of the ulcer may become irregular by unequal extension in the periphery, or by the coalescence of two or more ulcers, or by partial cicatrization. Simple ulcers, especially when seated near the lesser curvature, have a tendency to extend transversely to the long axis of the stomach, thus following the course of the blood-vessels. By this mode of extension, or more frequently by the coalescence of several ulcers, are formed girdle ulcers, which more or less completely surround the circumference of the stomach, oftener in the pyloric region than elsewhere.
As the ulcer extends in depth it often destroys each successive layer of the stomach in less extent than the preceding one, so that the form of the ulcer is conical or funnel-shaped, with a terrace-like appearance in its sloping edges. The apex of the truncated cone, which is directed toward the peritoneum, is often not directly opposite to the centre of the base or superior surface which occupies the mucous membrane, so that one side of the cone may be vertical and the other sloping. In the half of the stomach nearer the lesser curvature the cone slopes upward, and in the lower half of the stomach it slopes downward. The usual explanation of its conical shape is that the ulcer exactly corresponds to the territory supplied by an artery with its branches. Virchow finds an explanation for the oblique direction of the funnel in the arrangement of the arteries of the stomach. These, coming from different sources, run along the curvatures of the stomach, and there give off symmetrically branches which run obliquely toward the mucous membrane, so that one of these branches with its distributive twigs (arterial tree) would supply a part shaped like an oblique funnel. One of the chief supports of the theory which refers the origin of simple gastric ulcer to an arrest of the circulation is this correspondence in shape of the ulcer to the area of distribution of the branches of the arteries supplying the stomach.
All ulcers do not present the conical form and terraced edges which have been described. These appearances are far from constant in fresh ulcers, and they are usually absent in those of long duration.