We have already discussed the tumors of the spleen arising slowly or rapidly from hyperaemia, and from the congestion of dyscrasic blood, as far as regards the mere increase of volume. We have now to examine them more closely in other points of view.

These tumors are observed in typhus, and in many typhoid states, as in cholera typhus, in pyaemia, and in anomalous exanthematic processes, as occurring from disorganization of the blood after erysipelas, scarlatina, miliaria, or rheumatism, as found in drunkards, and in acute tubercular affections; they occur as a result of suppressed menstrual or hemorrhoidal discharge, of intermittent fever, of rickets, of lues and mercurial cachexia, and of many dyscrasic tubercular affections.

These tumors differ in character, and are owing partly to the hyper-aemia, partly to the deposition of an anomalous fibrous product in the parenchyma of the spleen. We find the greatest difference in the consistence of the tumors; but the chronic indurated tumors, are undoubtedly soft at first, and subsequently attain greater hardness, according as the deposit is more or less coagulable. The same remark applies to the color of the tumor, which at first is undoubtedly red, but subsequently becomes paler in proportion as the coloring matter is absorbed, and the hyperaemia is forced to yield to the compression exerted upon it by the deposit. We find, as regards other qualities, that the morbid product offers very prominent varieties, which we will examine in the analysis of the chief tumors that follows; the finer, though not less different characters we leave to another department of science, which, though not yet cultivated, promises many and very important results.

a. Among the tumors which accompany acute diseases of the blood, those of typhus are distinguished by their rapid and extensive increase, by their lax tissue, both of which circumstances sometimes predispose to rupture, and by the dark-red color of the parenchyma. This variety originates in stasis affecting the vascular system of the fundus ventriculi, and in the deposition of a very lax, pultaceous, semi-fluid, blackish-red, dirty violet, or lighter-colored purplish mass, varying in amount, and resembling the pulpy medullary matter found in the typhous mesenteric gland. If this substance is deposited rapidly to a large amount, the fibrous trabeculae of the spleen are rendered soft and friable by extension; and if the deposit is very soft, the viscus presents fluctuation.

The tumors occurring in the other acute dyscrasiae above alluded to, are more or less allied to this one. When accompanying universal acute tuberculosis, the eliminated mass, partially at least, at once assumes the characters of tubercle. The spleen may increase from a slight enlargement to three, four, five, and six times its normal size.

Tumors occurring after suppression of the above-mentioned hemorrhages do not generally become a subject of anatomical research until they have attained a very considerable size. They are most probably the result of repeated typical (typische) hyperaemise, and would be found at their commencement to be of slight consistency, and of a red color. A coagulable fibrinous deposit, however, takes place, and the tumor, therefore, in proportion to the amount of coagulation, becomes hard, elastic, and indurated, the parenchyma is reddish-brown, of the color of fresh muscle, and presents on section a fleshy (sarcomatous) appearance; by degrees the coloring matter is absorbed, the organ then presents a pale red, yellowish, or reddish-white appearance, and resembles fibrine that has been washed. During the hypersemise the fibrous trabecule also increase in quantity and toughness, so that the tumor becomes more resistant; the fibro-serous capsule is also rendered more opaque, and is thickened; it is invested with a cellular pseudo-membrane, resulting from peritoneal inflammation, and is thus attached to the abdominal parietes. The deposit gradually increases to such an extent as to induce a compression of the vascular portion of the spleen, and to render it impermeable to injections; for the same reason, the tumor gradually becomes paler, and a vicarious development of the vessels at the fundus of the stomach ensues.

The third variety of splenic tumors bears a general affinity to those accompanying the above-named cachexise, but the deposit that occurs in them and is substituted for the parenchyma of the organ much resembles bacon in consistency and appearance; the organ on section offers a very smooth surface, a dull, lardaceous (speckig, baconny), waxy gloss, and its superficial layer appears partially transparent; the spleen is hard, but breaks with a peculiar fracture; it presents a color varying from dark purple to pale red, and the blood contained in the vessels is pale and serous; this variety of splenic tumor is often coincident with the analogous lardaceous infiltration of the liver (vide p. 100): it may, however, occur in an isolated form, or complicated with a similar affection of the kidneys (a variety of Bright's disease). Like the other varieties, this tumor may attain an extreme size, and dropsy, and especially ascites, are common results.

b. We have lastly to advert to the fact that many cases of swelled spleen depend upon the formation of certain corpuscles, in addition to the coexisting hyperaemia. These small bodies are quite distinct from the Malpighian corpuscles, found in the spleens of some graminivora; they are minute grayish-red, or grayish-white, opaque, soft, deliquescent, vesicular substances, of the size of a millet-seed, which occupy the parenchyma of the spleen. They accompany a morbid development of the abdominal lymphatics, and especially of the follicular apparatus of the intestinal mucous membrane, with turgescence of the mesenteric glands, occurring in those affections of children and young subjects, which we have spoken of at page 61; they are also found in typhous affections of these organs, and of the spleen, and indicate a predominance and qualitative derangement of the lymphatic system. They are consequently also found complicated with acute and chronic tumors of the spleen, and are not to be confounded with acute tuberculosis of that organ.

The consistency of the spleen, as may be gathered from the above remarks, depends almost entirely upon the state of aggregation of the parenchyma, or of the morbid product which has replaced the latter. The condition of the fibrous tissue also influences it to a certain extent, but it varies much even within the limits of its physiological condition. The two extremes constitute softening and induration of the spleen, which we have already examined in their strict sense.

In very rare cases, the black softening of the tissues of the fundus ventriculi, is accompanied by a similar affection of the splenic tissue, which is converted into a black, carbonaceous, tarry, semi-fluid mass, originating in the vascular system.