SYMPTOMATOLOGY.—Lardaceous disease of the spleen is usually associated with similar disease of other organs—the liver, kidneys, stomach, intestines, heart, etc.—and its symptoms are so frequently accompanied by those of the affection that has given origin to it that it must always be difficult to distinguish them as attributable to the condition of the spleen itself. Profound anæmia with an appearance of cachexia is always present in advanced cases. Milder cases may reveal themselves by no signs. The symptoms arising from other parts implicated in the degeneration may completely mask those depending upon the spleen. When the stomach is involved, vomiting and hæmatemesis even to a fatal termination may occur, or uncontrollable diarrhoea from intestinal changes may supervene. Splenic enlargement is not unusually accompanied by enlargement of the liver. Ascites, however, is always a rare accompaniment.
Rarely, the spleen attains enormous size, and may then occasion sensations of weight and tension, and occasionally acute pain from implication of the capsule in inflammatory action. When the organ can be felt through the abdominal walls it will generally be hardened, painless, and with its boundaries much thicker and rounder than normal.
PATHOLOGICAL ANATOMY.—As has been already remarked, lardaceous disease of the spleen is observed in two forms. In both the spleen is enlarged and hardened. Its structure presents a tough, waxy consistence, and the organ has entirely lost its friability. In sago spleen, light-brown or grayish waxy bodies are scattered throughout the splenic structure. The pulp may remain quite healthy, or it may also be involved. These sago-like bodies correspond to the enlarged and lardaceous Malpighian corpuscles, and stand out with some prominence from the general surface. They may vary in size from that of a pinhead to that of a small pea. The color of the spleen may shade from a pale fawn color to a reddish-brown. In many cases where the parenchyma is involved there will be exhibited scattered areas of semi-transparent, wax-like material.
In the diffusely lardaceous spleen the organ is enlarged throughout, pitting to pressure, and upon section presenting a waxy, semi-translucent appearance, usually of a reddish-gray, but sometimes of a deep-red, color. Instead of a pulpy, easily broken-down condition of the splenic parenchyma, there will be found a dense tissue that can be cut into tough, glistening slices. Minor degrees of the change cannot be readily detected by the unaided eye, and even in advanced cases the judgment will often be at fault. Under these, and in fact under all circumstances a correct conclusion as to the nature of a given change can only be reached after the employment of reagents that exert peculiar influences over the lardaceous material. The action of iodine upon this material is quite characteristic. If a watery solution of iodine with iodide of potassium be applied to the cut surface of the suspected organ, the normal portions will be stained a yellowish color, while those parts that have undergone lardaceous degeneration will assume a rich mahogany red or brown, which will become violet or purple upon addition of sulphuric acid. This latter reaction is not constant, and may usually be omitted. Cornil has recently proposed as a test a solution of methyl-aniline-violet, which possesses the property of staining lardaceous matter red, while ordinary tissues will be stained a deep, bright blue. This reaction possesses the advantage of being permanent and very delicate, and on that account preferable for microscopic examination of specimens. According to Cohnheim, this reagent enables one to distinguish commencing lardaceous change.
In lardaceous disease of the Malpighian corpuscles the alteration will be found to begin in the arterial twig to which the corpuscle is attached, soon extending to the entire tissue of the corpuscle, which it causes to enlarge considerably. When the splenic pulp is attacked it is said to be the vessels of the pulp that are first involved. It is held by most pathologists (Virchow, Kyber, etc.) that the change is chiefly seated in the muscular coat of the small arteries, but that the intima is also very frequently affected, and that occasionally all the coats are involved. Thence the degeneration spreads to the cells and nuclei of the splenic tissue. Later investigations, however, seem to make it probable that the lardaceous degeneration is mostly limited to the connective-tissue trabeculæ and walls of the venous sinuses; that the pulp-cells are for the most part not implicated, but that they disappear in consequence of the pressure of the ever-increasing lardaceous material and the consequent anæmia (Cohnheim, Ziegler).
DIAGNOSIS.—This will depend more upon the history and concomitant symptoms and general condition of the patient than upon any positive evidence to be gained by special reference to the spleen. In a patient predisposed to lardaceous degeneration by any of the influences enumerated above the presumption in favor of splenic lardaceous disease is strong if, in addition to splenic enlargement, there is evidence of hypertrophy of the liver and albuminuria, indications of the participation of other organs in the process, and an anæmic and cachectic appearance of the individual always observed in advanced degrees of the degeneration.
PROGNOSIS.—The prognosis is almost always unfavorable, not so much on account of the splenic condition as from the general depreciation of the powers of life. The disorder being progressive, the tendency is toward death by complications resulting from degenerations of other organs. And yet it seems quite probable that mild grades of lardaceous degeneration may be entirely recovered from occasionally; but this will be almost invariably in cases where the spleen alone is implicated. At all events, when not advanced it may be long held in abeyance. The duration of the disease generally is indefinite and may cover a space of years.
TREATMENT.—The treatment of lardaceous degeneration of the spleen will consist rather in combating its exciting causes than in efforts directed toward the condition of the spleen itself. It may, however, be possible to effect some good by resorting to remedies supposed to be useful in subduing ordinary splenic enlargement.
Echinococcus of the Spleen.
Echinococci invade the human body in the United States far less frequently than in many other countries, where the canine race occupies much closer relations with man (as in Iceland). The echinococci are the larval forms of Tænia echinococcus, a tape-worm of minute size inhabiting the intestinal tract of the genus Canis, more especially that of the dog. The ova of the tæniæ are voided in countless numbers in the feces of their hosts. Still unhatched or in an embryonic form, they are thence conveyed through the medium of water or otherwise to the stomach of man, whence the embryos (scolices) escape into the tissues and develop into ordinary hydatid cysts. Rare as is this affection in the human body, it is relatively extremely uncommon as implicating the spleen, and recorded instances of its occurrence are not numerous. Hydatids of the spleen may coexist with those of other parts, and in occasional instances are said to be secondary to these. They are commonly encountered about the middle period of life, and appear to affect the sexes in equal proportions.