The condition of the bile-ducts is of great interest in view of the frequency of jaundice as a symptom in relapsing fever, and most authorities unite in saying that they present no lesions capable of explaining it.
The gall-bladder is usually found full of dark bile, but there is no such degree of inspissation, except in rare instances, as could interfere with its passage through the ducts. Murchison quotes the statement of Peacock that in some instances the bile was thick and viscid, so as apparently to cause obstruction, but all observations agree in showing that this is exceptional. The mucous membranes of the larger ducts may present evidences of slight catarrhal inflammation, but in nearly all cases where they have been carefully examined, even when jaundice had been marked, they have been found patulous and free, so that the jaundice cannot be regarded as due to obstruction of the larger ducts save in rare instances (Pastau). In further confirmation of this may be stated the fact that there is no want of bile in the duodenum and feces.
On the other hand, a careful consideration of the lesions of the substance of the liver will show that it would be most improbable that the minute biliary ducts in the areas most affected should escape implication. Münch, who investigated this subject carefully, found that there was a catarrhal state of the fine bile-ducts in every case of relapsing fever with jaundice; and Litten found the smallest ducts plugged with bile-stained pellets of mucus. It would appear, therefore, that in many cases at least the jaundice is really obstructive in its origin, the seat of the obstruction being in the too-rarely examined minute bile-ducts, though further investigation of this interesting question is required.
The clinical bearing of these conditions has been fully discussed in the appropriate section.
The changes in the spleen are constant, and even more remarkable than those in the liver. It is enlarged with rare exceptions, and especially so if death has occurred during the febrile stage. Upon the subsidence of the fever the spleen probably returns to its normal size more rapidly than the liver. The more common extent of the enlargement in our own cases was from ten to eighteen ounces, though we found the spleen in one case weighing twenty-nine and a half ounces and in another forty-four and a half ounces. In neither of the latter instances was there any reason to suspect malarial complication. The most extensive enlargement we have found recorded is sixty-eight ounces in a case reported by Küttner.34
34 Schmidt's Jahrb., 1865, vol. cxxvi.
There is usually a correspondence between the stage and extent of the splenic and hepatic lesions, but this is not invariable, and one or the other organ may present a far higher degree of enlargement or much more intense interstitial changes. It may be mentioned, moreover, that in some unusual cases the lesions of the lungs, such as ecchymoses and hemorrhagic infarctions, may be disproportionately marked as compared with those of either the liver or spleen.
The capsule of the spleen often presents a mottled look, with at times large purplish ecchymoses; it is apt to be more or less opaque, and local peritonitis, with thin layers of plastic exudation often forming friable adhesions with the abdominal wall, may exist.
In one of our cases the capsule presented a small perforation or rupture, with an exudation of plastic lymph over an area of four by six inches, and diffuse peritonitis, with effusion of bloody liquid with shreds of lymph throughout the abdominal cavity. This fatal termination is fortunately rare, but there are several other instances on record. The splenic pulp may retain its consistency and firmness, even in cases that have run a long course; but more frequently it is softened, and may be almost diffluent. The pulp is often swollen, so that when cut it projects above the section. The color is darker than normal, and often is of a deep maroon color. This swelling is due to enlargement of the blood-vessels, associated with great increase of the cellular elements of the pulp and with enlargement of the Malpighian corpuscles.
When death occurred early in the disease we found these bodies grayish or grayish-yellow in color and of the size of hempseed, so that the section very thickly studded with them closely resembled shad-roe, and this stage of the lesion is frequently described in our notes as the shad-roe spleen. Subsequently, the Malpighian bodies enlarge still more, and stand out above the section a line or more in diameter, and of a lighter color; not rarely, several of them come in contact, and thus form a considerable mass of irregular shape, resembling the infarctions described below.35 It is probable that central softening may occur later in the Malpighian bodies, though we are inclined to regard the puriform collections frequently found as chiefly due to the disintegration of hemorrhagic infarctions or of embolic patches. Of these, hemorrhagic infarctions are by far the most common and present the familiar appearances. They may be quite numerous, superficial, or deep-seated, and of variable shape and size. At first dark reddish, firm, and sharply separated from the surrounding pulp, they grew reddish-yellow or yellowish later, softened in the centre, and eventually were transformed into puriform collections. Doubtless, in a large proportion of cases that recover such infarctions exist and are slowly absorbed. Ponfick has shown that these are venous infarctions, the arterioles leading to them being patulous. True arterial embolism does, however, occur, though much more rarely (Ponfick, Murchison), giving rise to firm, wedge-shaped infarctions at the periphery of the spleen, which may undergo degenerative changes similar to those above described. The resulting abscesses may burst into the peritoneum, pleura, lung, or bowel. The microscopic appearances have been most fully described by Ponfick, our own comparatively meagre observations having accorded entirely with his subsequent accurate description. The cells of the swollen pulp contain red blood-discs and pigment, and some present collections of bright granules. The lymphoid cells of the Malpighian corpuscles are at first in a state of cloudy swelling with multiplication of their nuclei, and later show marked granular fatty degeneration.