Part 188

Sarcoma of the pancreas occurs with extreme rarity. It is impossible during life to distinguish it from carcinoma.

Tubercle of the gland is infrequently met with. Some pathologists deny its occurrence, and believe that the cases recorded as such are merely instances of caseous degeneration of the neighboring glands. When it does occur, it is always secondary, the primary disease being situated in the lungs or intestines. The alterations in the gland consist in the development of cheesy masses or of miliary granulations in the connective tissue between the acini. The condition gives rise to no definite symptoms, and its diagnosis during life is impossible.

DEGENERATIONS OF THE PANCREAS.

Fatty Disease of the Pancreas.

Two forms of fatty degeneration occur, either separately or combined--namely, fatty infiltration and fatty metamorphosis.

Fatty infiltration consists of a true hypertrophy of the fat-tissue normally existing in the gland, or of an increase and extension into the gland of the peripancreatic adipose tissue. Yellow bands and masses of fat-tissue appear between the acini, and by constantly increasing in size lead gradually to a total atrophy of the cells of the acini. The canal of Wirsung contains a fatty liquid. These changes are found associated with fatty liver, heart, and omentum, in drunkards especially.

Fatty metamorphosis of the gland consists of a change analogous to fatty metamorphosis of other organs. When hyperplasia of the interstitial connective tissue is absent, the organ is flaccid, soft, and diminished in size; the acinous structure remains distinct, though the acini and ducts are filled with a fatty emulsion: after this is discharged or absorbed the gland appears as a flaccid band, and finally becomes entirely atrophied. Fatty metamorphosis occurs in drunkards, in diabetes, in advanced age, in cancer, phthisis, and other wasting diseases.

Neither form of fatty disease gives rise to symptoms by which it can be recognized during life.

Albuminoid Degeneration of the Pancreas.

This is only found in combination with amyloid change in other organs of the body, and a diagnosis cannot be made.

{1129} Hemorrhages into the Pancreas.

Hemorrhages into the pancreas may be divided into three classes.

The most common form depends upon passive hyperæmia, the result of chronic diseases of the heart, lungs, or liver. In this condition the effusion of blood coexists with chronic inflammatory changes in the interstitial connective tissue. The appearance at first is of minute bloody points scattered throughout the areolar tissue; later, these change into round or oval pigment masses, or spaces containing reddish serum and surrounded by thickened, rust-colored, irregular walls.

The second class includes the rare cases of hemorrhage resulting from the rupture of one of the large blood-vessels of the gland, and due to some pre-existing change in the vessel walls. In these the pancreas is enlarged, may be converted into a sac containing blood, either fluid or coagulated or partially crystallized according to the duration of life after the hemorrhage has taken place, and a ruptured blood-vessel may be readily discovered on dissection.

The condition in which, without any evidence of passive hyperæmia or gross vascular lesion, the entire pancreas become hemorrhagic, constitutes the third class. The gland is then dark-red or violet in color, the meshes of the interstitial tissue are filled with recent or altered blood, and the acini are stained of a dull-gray hue. The hemorrhage may extend to the connective tissue surrounding the gland. Finally, the organ becomes soft, the peritoneal covering sloughs, and fragments of broken-down gland-tissue escape into the peritoneal cavity. These lesions are so analogous to those which attend thrombosis occurring in other organs that their dependence upon the same cause seems probable.

The first form of hemorrhage is unattended by special symptoms. In the second a pulsating tumor may suddenly appear in the epigastrium, and the ordinary indications of hemorrhage--vomiting, fainting fits, cold extremities, feeble pulse, and general exhaustion--are present. Death may occur suddenly or the patient may linger on for months. In the third condition death usually occurs very suddenly, probably from pressure upon the sympathetic ganglia. There are no symptoms, and the rapid termination prevents the development of general peritonitis, which would otherwise occur from the sloughing of the peritoneum.

There are no indications for treatment.

OBSTRUCTION OF THE PANCREATIC DUCT.

Obstruction of the excretory duct is a frequent occurrence in pancreatic disease, and is due to two classes of causes--namely, 1st, pressure from without; and, 2d, closure of the canal by catarrhal swelling of its mucous membrane or by calculi.

In the first class may be placed obstruction depending upon contraction occurring in sclerosis of the gland, upon carcinoma of the head of the gland, upon peripancreatic adhesions and indurations, upon the {1130} presence of large gall-stones in the ductus choledochus, and upon carcinoma of the pylorus and duodenum and enlargement of the neighboring lymphatic glands.

In catarrh of the canal of Wirsung the obstruction results either from simple swelling of the mucous membrane or from the presence of a plug of tough mucus.

The formation of pancreatic concretions is by no means a rare event, though these calculi are met with far less frequently than either gall-stones or salivary concretions. They result from precipitation of the inorganic ingredients of the pancreatic juice, and are usually seated in the main duct, although they may be situated in the smaller branches. They may be single or multiple, as many as twenty having been counted in one gland. In shape they are spherical, oval, or branched, with sometimes a smooth, at others a spiculated, surface; their size varies from that of a minute granule to a small walnut; they are usually white or grayish-white in color, but may be black; and are composed of the carbonate of lime or of a combination of the carbonate and phosphate with oxalate of lime. Coincidently with these calculi it is common to find concretions in the kidneys and gall-bladder.

Concretions composed of insoluble protein substances have also been found in the pancreatic ducts (Virchow).

The most probable causes of the formation of pancreatic calculi seem to be catarrhal conditions of the mucous membrane of the ducts and an alteration in the chemical composition of the secretion.

Whatever the cause, the obstruction, when complete, leads to retention of the secretion and the formation of retention cysts.

When the obstruction is situated at the duodenal extremity of the duct, the canal and its secondary branches are either uniformly dilated or sacculi are formed. These sacculi are round or oval, vary greatly in size, sometimes reaching the dimensions of the fist or of a child's head; they may be single, or several of them may be present, differing in size and causing irregular projections of the outer surface of the gland. When the obstruction occurs at some point in the course of the duct, the dilatations and sacculi are found only behind the point of occlusion. The small cysts contain a fluid resembling the pancreatic juice; the larger, a whitish, chalky fluid, which in old cases may contain white friable concretions composed of carbonate and phosphate of lime, and become purulent, or be stained bright red or chocolate-colored from the occurrence of hemorrhage. In such instances hæmatoidin crystals can be discovered by the microscope. The interior of the dilated ducts and of the retention cysts is lined by a single layer of thin flat cells, with irregular edges and with oval flat nuclei. The walls are thickened, and composed of superimposed layers of laminated connective tissue separated from one another by flat nucleated cells. The secreting structure of the gland undergoes atrophy from pressure, or fatty metamorphosis takes place, and, although the gland is increased in size from the presence of the cysts, its functional power is lost.

In addition to causing obstruction of the duct of Wirsung and the changes mentioned, pancreatic calculi may produce induration, atrophy, acute inflammation, or even suppuration of the surrounding glandular tissue.

{1131} SYMPTOMS AND COURSE.--The main feature is the presence in the epigastrium of a rounded, smooth, fluctuating, painless tumor. There are also indications of the absence of the pancreatic secretion from the digestive tract--notably, emaciation, general debility, and the appearance of fat in the stools. Jaundice resulting from a coincident obstruction of the bile-duct is a frequent symptom, and melituria has been noted in some cases. It is probable, too, that the passage of a calculus along the duct may give rise to pain resembling in character and distribution the pain of hepatic colic.