A growth which involves the surfaces or curvatures of the stomach without implication of an orifice is often accompanied by such severe pain, vomiting, and haematemesis that its differential diagnosis from simple ulcer may be a matter of considerable difficulty.

It is usually stated that simple gastric ulcer is a disease of early adult life, and carcinoma one of middle or advanced age, and that the former is most frequent in women and the latter in men. If these statements refer solely to the acute variety of gastric ulcer, the distinctions they imply are correct, but if they include the ordinary chronic form of the complaint, they are not only incorrect but actually misleading. We have shown elsewhere that more than one half of the cases of chronic ulcer commence between thirty and fifty years of age, and that the disease is more common at this period in men than in women, while carcinoma is by no means infrequent between thirty and forty, and is equally prevalent in the two sexes. We lay special stress upon these facts, because we have known many serious errors of diagnosis to ensue from an implicit reliance upon the supposititious differences in the age and sex incidence of the two diseases.

The chief points of distinction between chronic ulcer and cancer are as follows : (a) In cancer, debility and loss of flesh usually precede the local phenomena, while in ulcer they rarely appear until a late stage of the disease. (6) In the former the pain is less dependent upon food, is more diffuse, and shows a tendency to increase and to become constant, (c) Nausea is most frequent in cancer, and retching and vomiting often occur when the stomach is devoid of food. In ulcer, on the other hand, emesis usually takes place at the height of the painful crisis, and is followed by immediate relief, (d) Profuse haematemesis is rare in the malignant complaint, while the rejection of small quantities of altered blood is frequently observed. In ulcer the haemorrhage occurs at irregular intervals and is very abundant, (e) Anorexia is an early and progressive symptom in carcinoma, and the tongue is often foul, while in ulcer the appetite is usually preserved, although the patient is afraid to indulge it, and the tongue is red and clean. (f) Free hydrochloric acid is rarely present in the vomit or the contents of the stomach in cases of carcinoma, while lactic acid may exist in excess. In ulcer the mineral acid is usually increased and the organic acid absent, (g) Microscopical examination of the vomit or washings of the stomach in malignant disease may detect the Oppler-Boas bacillus, cancer cellnests, or epithelial cells showing irregular mitoses, (h) Leucocytosis after meals is often absent in cases of cancer, but is always present and may be slightly increased in chronic ulcer, (i) A tumour connected with the stomach is the rule in cancer, but the exception in ulcer. (J) In carcinoma the sulphocyanide of potassium in the saliva rapidly diminishes and eventually disappears, while in ulcer the salt can be detected until a late stage of the complaint, (k) A milk diet often increases the abdominal pain or discomfort of the former complaint, and the patient continues to lose both flesh and strength when restricted to liquids; in the latter, abstention from solid food is followed by the immediate amelioration of the symptoms, and milk almost always agrees well. (I) Carcinoma usually gives rise to secondary deposits in the liver, peritoneum, or skin of the abdomen, to enlargement of the glands above the clavicle, or to venous thrombosis, and usually runs its course in less than twelve months. In ulcer the physical signs remain unaltered and the symptoms may persist for many years.

A carcinomatous tumour of the body of the stomach has to be distinguished from that produced by a foreign body in the viscus, from the pancreas in a normal or diseased state, from a retro-peritoneal cyst, and from a tumour of the colon.

A hair-ball constitutes the variety of foreign body most liable to be mistaken for a growth of the gastric wall. This interesting condition, however, is practically confined to young women, and usually commences before the age of puberty. The mass is hard, superficial, dull on percussion, painless, very movable, and of extremely slow growth. The symptoms which accompany it are those of chronic dyspepsia, and careful inquiry will usually elicit a history of hair-swallowing (see Part II.).

When great emaciation exists and adhesion of the pylorus to the liver has induced a dislocation downwards of the dilated stomach, the uncovered pancreas may sometimes be felt as a hard transversely situated mass just above the umbilicus. The apparent tumour, however, does not move with respiration like a gastric growth, is incapable of displacement by the hand, does not increase in size, is deeply situated in the abdomen, and is found to lie above the lesser curvature of the stomach.

A cyst of the pancreas usually comes forward between the great curvature of the stomach and the transverse colon. Over its exposed portion the percussion-note is dull, while elsewhere the superimposed stomach or bowel gives rise to a resonant note. The outlines of the mass are ill-defined, the general shape is globular, and no movement can be detected upon respiration or pressure. Inflation of the stomach shows that viscus to be in front of or above the tumour, while the symptoms and signs of gastric carcinoma are invariably absent.

In those rare cases where a small cyst forms in the head of the pancreas and compresses the second part of the duodenum, the symptoms of gastric dilatation, combined with the detection of a tumour, may give rise to much difficulty of diagnosis.