A morbid growth of the pylorus is chiefly attended by the symptoms and signs of dilatation of the stomach, and has therefore to be distinguished from two other conditions which produce stenosis of the outlet, namely, the cicatrisation of a simple ulcer and adhesions between the pylorus and the gall-bladder or liver.
The malignant disease occurs with equal frequency in the two sexes, and seldom appears before the age of forty-five. Cicatricial stenosis affects both sexes, and is most common between thirty and fifty years of age. The pyloric obstruction which results from cholecystitis is far more common in women than in men and develops at a comparatively early age.
The previous history of the patient is always of great importance. In carcinoma the general health is usually excellent until the onset of the disease ; in ulcer the symptoms of gastric dilatation are preceded by severe pain after food and often by one or more attacks of haematemesis ; while in disease of the gall-bladder there is usually a history of severe attacks of pain, accompanied by vomiting and shivering, and sometimes followed by icterus. In each complaint there are vomiting, flatulence, acidity, nausea, loss of appetite, and constipation ; but these symptoms develop much more slowly in the simple than in the malignant complaint, and are attended by less rapid loss of flesh and an absence of cachexia. In addition to these differences of symptomatology there are three physical signs which greatly help to distinguish the malignant from the benign forms of pyloric stenosis.
In about 71 per cent, of the cases of carcinoma of the pylorus a growing tumour can be detected by palpation, being usually tender on pressure and often becoming adherent to the liver or other neighbouring organ (p. 171). Examination of the contents of the stomach usually shows an absence of free hydrochloric acid, with an excess of lactic acid and the presence of the Oppler-Boas bacillus; while the microscope may reveal particles of cancer tissue or epithelial cells which exhibit atypical mitoses (p. 161). At a later stage secondary deposits are frequently found in the liver, peritoneum, or skin of the abdomen.
Pyloric stenosis due to ulcer is accompanied by hyperchlorhydria without either lactic acid or the Oppler-Boas bacillus, and is rarely attended by a palpable tumour ; while in cases of adhesions between the pylorus and the gall-bladder free hydrochloric acid may usually be detected in the gastric contents and the organic acid is absent. As a rule these several distinctions, taken in conjunction with the much longer duration of the benign diseases, and their greater amenability to treatment, allow the latter to be readily distinguished from the malignant complaint; but occasionally both a simple ulcer and pyloric adhesions are associated with a palpable tumour, which greatly complicates their diagnosis.
(a) It is only in very exceptional cases that an abnormal degree of thickening at the base of an ulcer gives rise to a tumour in the region of the pylorus. In such the mass usually resembles a walnut in size and shape, or takes the form of a hard ridge or plate ; but sometimes it is so large as to produce a tumour visible to the naked eye.
Thus, Clarke has recorded the case of a man, forty-five years of age, who had suffered for some time from pain after food and vomiting. The right side of the epigastrium was swollen, and presented a rounded tumour about the size of an orange. After death, which occurred from peritonitis, the pyloric end of the stomach was found to be occupied by a tumour the size of two fists, to which the neighbouring viscera were adherent. The mass was composed of pale tough fibrous tissue, which surrounded two deep ulcers with ragged walls. Microscopic examination showed that the tumour was composed entirely of inflammatory tissue. Three or four similar cases have come under our own observation, of which the following is a good example.