The other condition in which the mesenteric nodes are especially involved is the cancerous. In this location, as in the omentum, sarcoma may be primary and endothelioma may occur, but carcinoma is never primary, although it invariably occurs as an extension from epithelioma or adenocarcinoma of the bowel. Otherwise cancer will appear here as an expression of metastasis. In all primary cancers of the intestine early involvement of the mesenteric nodes may be looked for, while involvement of everything in the vicinity, even the aorta or spine, will occur in due time, often with more or less breaking down. There would be little justification for attacking any cancerous portion of the mesentery or any cancerous nodes unless the primary lesion could be radically removed. Generally speaking, in bowel cancer invasion of the deep-seated nodes imparts to the case such an unfavorable aspect as to justify only palliative (anastomotic) rather than radical measures.
CYSTS OF THE MESENTERY.
Cysts of the mesentery are, in the main, similar to those met with in the omentum ([Fig. 631]). A peculiar form of mesenteric cyst is produced by obstruction and consequent dilatation of one or more of the lacteals, and is known as chyle cyst. It may attain considerable size and occur in multiple form. The contained fluid is naturally milky and corresponds to that seen in chylous ascites and hydrocele. These lesions are only recognized after exploration. When found they are to be extirpated, on general principles, usually by enucleation, with ligature of the connecting lacteals and avoidance of all unnecessary disturbance of blood supply.
Fig. 631
Cyst of the mesentery, containing clear fluid. The hour-glass constriction passes through the layers of the mesentery. (From a case occurring in Richardson’s practice.)
THE SPLEEN.
The spleen is often an object of surgical interest, not alone because of the frequency with which it is enlarged in the course of the acute surgical infections, but because it is something more than a reservoir for blood. Thus it seems to enlarge to accommodate blood forced in from the exterior under conditions of extreme exercise, etc., and in the higher vertebrates it seems to be a place where blood corpuscles are destroyed, especially those which are already disintegrating, rather than one in which they are manufactured. It is claimed by Ehrlich that the splenic enlargement of the infectious diseases is produced mainly by the products of disintegrating leukocytes which are allowed to accumulate.
ANOMALIES OF THE SPLEEN.
Of the congenital anomalies or defects the surgeon is mainly interested in the fact that supernumerary spleens are common, being found perhaps in one out of four bodies varying in number up to thirty or forty, located near the hilus in the gastrosplenic omentum, in the great omentum, or even in the pancreas. Doubtless after some splenectomies no peculiar symptoms are produced, which is due to the fact that some of the supernumerary organs have taken up the splenic function. The spleen varies in shape to such an extent that the notch upon which so much stress is often laid in diagnosis will not always be found along the anterior border. In cases of transposition of the viscera the spleen may be found on the right side. It has been found in the sacs of large umbilical hernias and in the left thorax after defects of the diaphragm.