GASTEIC CAECINOMA. 357 



wall, lies in the bed of the stomach chamber, and may be opened 

 by ulcers on the posterior wall which have contracted adhesions. 

 The coronary veins may be eroded, or even the splenic or portal 

 trunks, although at first sight, on account of the interposition of 

 the pancreas, erosion of the two latter would appear impossible. 

 Haemorrhage from veins is uncommon, and when attacked by a 

 gastric ulcer they are much more likely to be concerned in the pro- 

 duction of portal pyaemia or secondary abscesses. As rarities may 

 be mentioned perforation of the hepatic artery, of the abdominal 

 aorta, and even of the left ventricle of the heart. 



A gastric perforation is occasionally circumscribed by adhesions 

 which have formed as the ulcer approached the peritoneal surface. 

 In such cases a more or less localised abscess may result, and the 

 patient escape general peritonitis. Such localised abscesses may 

 lie in the dome of the stomach chamber between the stomach 

 and left wing of the diaphragm, or between the stomach and 

 its bed. They may come forwards and present in the epigas- 

 trium, being limited below by omental adhesions to the anterior 

 abdominal wall. Fistulas are rarely formed as the result of simple 

 ulcer ation. They may appear in the epigastrium or unite the 

 stomach with the colon, small intestine, or even gall-bladder. 

 Earely an adherent ulcer perforates into the subperitoneal tissues, 

 giving rise to suppuration or emphysema. 



The cicatrices left by ulcers may produce a bilocular or hour- 

 glass stomach, and may, if situated in the pyloric region, give rise 

 to obstruction to the exit of contents and to dilatation. 



Carcinoma of the stomach arises from the epithelium of the 

 gastric glands, and so may be either columnar- or spheroidal- 

 celled. It is most frequent in the pyloric region, but may 

 originate at the oasophageal opening or in some other part. The 

 pylorus and adjacent part of the greater curvature are the 

 only portions accessible to palpation. The transpyloric line 

 (Fig. 49, p. 362), which bisects the distance from the top of the 

 manubrium sterni to the pubic symphysis, indicates the level of 

 the pylorus, but the weight of a tumour or the drag of a dis- 

 tended stomach may dislocate the pylorus considerably. The 



