A localised collection of pus as the result of perforation occurs in 3 to 5 per cent, of all cases of carcinoma of the stomach, and is rather more frequent in disease of the cardia than of the pyloric end of the organ.

When the abscess is small in size and deeply situated, it is seldom accompanied by any special symptoms. As a rule, there is some increase of the abdominal pain, which, if previously intermittent, becomes constant and may be associated with frequent retching. The temperature is somewhat elevated, and chills, or even rigors, may occur, while increasing debility and anaemia are invariably present. The physical signs chiefly consist of fulness and tenderness of the epigastrium. Death usually occurs from exhaustion, and the discovery of an abscess at the necropsy is often quite unexpected.

The larger collections of pus generally form beneath the left wing of the diaphragm, or between the stomach and the abdominal wall. In the former case pain and dyspnoea are prominent symptoms, rigors are not infrequent, and the temperature may be elevated several degrees. The epigastrium and left hypochondrium are distended and tender on palpation ; the abdominal walls are rigidly contracted, and no movement of the diaphragm can be detected on deep inspiration. Within a short time the affected side of the chest becomes enlarged, and its lower ribs are thrown outwards, so that the costal angle is increased. The intercostal spaces are also widened, and may bulge to some extent. The displacement of the liver and spleen is often obscured by the tenderness and rigidity of the abdominal wall, but careful percussion will usually show that the left hepatic lobe projects into the epigastrium. In almost every instance the heart is tilted upwards, and its apex may be felt in the fourth intercostal space, rather to the left of its normal position. The base of the left lung is compressed and partially deprived of air, so that the percussion-note over the left posterior base is comparatively dull and the respiratory murmur diminished. This condition is distinguished from pleuritic effusion by an increase of tactile fremitus and vocal resonance over the affected area, and by the occasional existence of moist crepitations. The presence of gas in the abscess-sac beneath the diaphragm gives rise to a tympanitic note over the front of the left chest as far upwards as the fourth rib, which may extend across the sternum to the right nipple-line and downwards to the right costal margin, where it merges with the hyperresonance of the epigastrium. On auscultation over the front and lateral aspects of the left chest the vesicular murmur is found to be either absent or replaced by loud amphoric breathing. The latter phenomenon is usually due to an alteration in the breath-sounds produced by their transmission through the gas-containing cavity; but it is also possible that in some cases a communication between the stomach and the abscess may permit an interchange of gas with each movement of the diaphragm. When the subphrenic abscess contains a large quantity of both pus and gas, metallic tinkling is often audible after coughing, or a loud succussion sound may be produced by movement of the body. Finally, it may be noticed that when two coins are clinked together over the abscess a bruit d'airain may be heard over the affected area.

A circumscribed abscess due to perforation of the anterior wall of the stomach is usually situated in the epigastric, left hypochondriac, or umbilical region, where it produces a rounded and tender swelling. Owing to the existence of adhesions the tumour does not move with respiration, nor can it be displaced by manipulation. The percussion-note over it varies according to its contents, being dull when they consist of fluid, but resonant when a large amount of gas is present.

An abscess situated behind the stomach in the lesser cavity of the peritoneum is rarely accompanied by any signs of importance, and in most cases moderate fever of a hectic type, and increasing debility and anaemia, are the only symptoms which indicate the existence of suppuration. If the pus bursts into the stomach, it may appear in the vomit.

The duration of life in cases of perigastric abscess varies according to the stage of the gastric complaint at which it ensues and the intensity of the local inflammation. If the sac is small in size, the fatal event may be postponed for several weeks; but when a large quantity of pus accumulates in the immediate vicinity of the diaphragm, death usually takes place within a week or ten days.