Splenomegaly

Splenomegaly, or megaspleenia (from Greek splen-spleen and megas-large), a term usually used to denote such (predominantly chronic) enlargement of the spleen that constitutes either the main or at any rate an extremely noticeable and essential feature in the overall picture of the disease. However, strictly speaking, it can be applied to any case of enlargement of the spleen if it clearly exceeds the normally observed acute or chronic "tumor" of it (approximately over 600-700 g in weight). In this so-called acute tumors of the spleen, although they can reach in some infectious diseases (typhus, sepsis, miliary tbc) very significant sizes (Kaufmann mentions a case of miliary tbc with a spleen of dimensions 21 x 14 x 7 cm), nevertheless they are usually not designated as splenomegaly, since in this condition this sign does not have any particularly outstanding value among other symptoms of the corresponding disease. "Chronic tumors" of the spleen, to which the term "splenomegaly" is mainly applied, can arise under the influence of extremely diverse factors, for which reason they are divided by various authors into different groups. Thus, Naegeli distinguishes S. of the following origin: 1) in hemolytic anemia (hemolytic jaundice), constitutional, hereditary and non-constitutional, acquired (see Anemia); 2) in pernicious anemia (see Anemia); 3) in polycythemia (see); 4) in disease of Albers-Schönberg (Marmorknochen) (see Osteopathies); 5) in reticuloses: Gaucher disease (see), Niemann-Pick disease (see); 6) in cirrhoses of the liver (see Cirrhoses of the liver, Hepatolienal diseases), Wilson disease (see), Banti disease (see); 7) in the so-called pericarditic false cirrhosis of the liver (see Cirrhoses of the liver); 8) in thrombocytopenia (see Werlhof disease); 9) in lesions of the portal vein and its branches (thrombophlebitic splenomegaly); 10) so-called siderotic splenomegalies (?); 11) infectious splenomegalies on the basis of syphilis, tuberculosis (chronic isolated tuberculosis of the spleen), lymphogranulomatosis (see), sepsis lenta, malaria, leishmaniasis (see), echinococcus (see); 12) in leukemic and aleukemic myeloses and lymphadenoses (see Leukemia, Aleukemia, Pseudoleukemia); 13) in neoplasms of the spleen. Lubarsch divides S. into 7 main groups with additional subdivisions in each of them, namely: I. Enlargement of the spleen in circulatory disorders: a) in the great circle (tumor lienis cyanoticus); b) in the portal vein system (thrombophlebitic S.). II. Enlargement of the spleen in blood diseases: a) in leukemias, b) in pernicious anemia, c) in hemolytic jaundice, d) in thrombocytopenic purpura, e) in erythremia (polycythemia), f) in so-called splenogenic anemias. III. Enlargement of the spleen in metabolic disorders: a) in obesity and diabetes mellitus, b) in diseases of Gaucher and Niemann-Pick. IV. Enlargement of the spleen in complex disorders (circulation and metabolism): a) in cirrhoses of the liver, b) in disease of Banti. V. Enlargement of the spleen in infections: a) acute, b) chronic (tbc, syphilis, lymphogranulomatosis, malaria, kala-azar and others). VI. Enlargement of the spleen in its neoplasms: a) primary, b) secondary. VII. Enlargement of the spleen due to the presence of animal parasites (echinococcus).-In general, both classifications cover all the main types of splenomegaly, complementing each other in details. For greater completeness, it remains only to mention the splenomegaly often observed, although not necessarily, in so-called congenital hematoporphyria (see Hematoporphyria, Porphyriauria) and caused by hyperplasia of the reticulo-endothelium of the spleen with abundant deposition of iron-containing pigment there. Among the listed forms of S., most have been described earlier (see the words indicated above). Therefore, in the present article it is necessary to dwell only on two. 1. Thrombophlebitic S. was first isolated as a separate nosological unit by French authors Dévé and Cauchois under the name "splenomegalie chronique avec anemie d'origine pylethrombosique". In this name not only are the main symptoms of this form listed, but the sequence of their development is also indicated. The matter concerns primary thrombosis of the portal vein, mostly with secondary thrombotic process in the splenic vein and veins of the stomach, as a result of which chronic S., repeated bloody vomiting (due to bleeding from dilated veins of the stomach or esophagus) and anemia occur. In addition to this main symptom complex, later authors indicated leukopenia, thrombocytopenia and moderate increases in temperature, especially in the initial periods of the disease, as frequently occurring signs. In this case, cirrhotic changes in the liver are absent even with very long duration of the disease, which sharply distinguishes it from cirrhotic S. and from morbus Banti, in which sometimes in late stages thromboses in the v. portae system can also develop, but of secondary origin, in connection with changes in the liver and spleen. Moreover, Eppinger, the author of the most detailed research on this issue, particularly emphasized the possibility of primary thrombosis of the splenic vein as the main factor of the suffering. Similarly, according to some (Eppinger, Naegeli), anemia cannot always be explained by bleeding, which in other cases are insignificant or even completely absent, but to a certain extent should be associated with enlargement of the spleen and with the inhibitory effect of the latter on the activity of the bone marrow. Histological changes in the spleen in thrombophlebitic splenomegaly amount to a picture of plethora and general fibrosis. It is expressed by strong, although uneven, blood filling of the sinuses, thickening of the capsule and trabeculae (the latter mainly in the vicinity of trabecular veins), roughening of the reticular framework, decrease in the number of cells in the pulp, atrophy and sclerosis of follicles and more or less numerous hemorrhages. The latter are located mainly subcapsularly and subsequently give rise to abundant deposits of iron in these places, partly in the form of accumulations of blood pigment, partly in the form of iron-lime impregnation of collagenous and reticular fibers (so-called scleropigment nodules).-As for the causes of thrombosis, they can be extremely diverse. Apparently in most cases the pathological process causing the formation of thrombus extends to the vein wall from the surrounding tissues, as observed for example in chronic peritonitis, in pancreatitis with fat necrosis, in various tuberculous or syphilitic processes in the portal area. Ulcerative processes in the intestine can play the same role, since they sometimes cause thrombosis of the mesenteric vein with possible continuation of the thrombus into v. lienalis or v. portae, as well as disintegrating cancerous tumors of the stomach or transverse colon, if they, adhering to lig. gastro-lienale, give rise to toxic phlebitis of the splenic vein, etc. Of course traumatic thromboses of the portal vein are also possible, and in infants in the first weeks of life with umbilical infection - transition of inflammation from the umbilical vein to the left branch of v. portae and further along its system both in proximal and distal directions. A process of this kind sometimes proceeds very slowly, not giving a picture of acute sepsis, as usual, but causing only chronic inflammatory changes in the blood vessels with mural or obstructive thrombosis, subsequent organization and canalization of the thrombus and persistent narrowing of the lumen. Finally in some rare cases of complete absence of any explanatory patho-anatomical data, "primary" thrombosis of the portal or splenic vein is spoken of as an independent disease of unknown origin. 2. So-called mycotic, otherwise scleromycotic, or siderotic S. (splenomycosis),-a morbid form which, as is now established, owes its appearance probably to an error of observation. The fact is that in the spleen in various forms of S. fibrous nodules, pigmented in yellowish or brownish-yellow color (scleropigment, or siderofibrous nodules) are often found. On microscopic examination in them bundles of straight or twisted threads, some whole some segmented, can be easily detected, part of which has a pale yellowish or greenish color and remains unstained, while another part, on the contrary, is stained with a dark color by hematoxylin, giving pictures of solid or two-contour lines. There can also sometimes be seen peripherally stained grains resembling microbial spores, and several larger figures in the form of a circle or segment of a circle, also with peripheral staining, often located at the ends of the threads. All the listed formations give a distinct reaction to iron, and partly also to lime.

Such nodules were first described by Gandy in 1905 and subsequently their existence was confirmed by a number of French and German authors, who pointed to the connection of these nodules with previous hemorrhages, and the above-mentioned formations were partly interpreted as the result of impregnation of various tissue elements (collagen, elastic fibers, etc.) with iron salts released during the breakdown of hemoglobin, with subsequent partial calcification of them, and partly as the result of precipitation of these salts in the tissues. In 1927, Nanta, who examined 20 spleens removed surgically for S. in Algeria and found the above-described scleropigment nodules in 15 of them, first expressed the view that the iron-impregnated formations in them do not represent tissue elements but mycelium, spores, and fruiting organs of the mold fungus Aspergillus, proof of which was that in three of these cases the said fungus was isolated from the spleen in pure culture. This view was accepted by many, mainly French and Russian authors, some of whom also obtained cultures of Aspergillus in the corresponding cases, and thus established a special form of 'fungal splenomegaly' (splenomycosis). However, immediately after the appearance of Nanta's works and his closest followers, as well as in subsequent years, very serious objections began to be raised from many sides, both against recognizing the formations found in the spleen as elements of the fungus, and generally against the existence of fungal S. First of all, it was pointed out that such formations can be found in S. of extremely diverse origins (Banti's disease, cirrhosis of the liver, polycythemia, hemolytic jaundice, etc.) and even in unenlarged or slightly enlarged spleens from the most varied cases (liver cancer, scars from infarctions, amyloidosis, etc.); further, that they occur not only in the spleen but also in many other organs where blood breakdown or blood pigment accumulation occurs (in the lungs in brown induration, in lymph nodes in hemosiderosis, in ovarian scars at the site of the corpus luteum, etc.); finally, that the arrangement and direction of the threads of this 'pseudomycelium' usually coincide with the arrangement and direction of the collagen, reticular, or elastic fibers of the given place, and that between them and the others direct transitions are often found. As for the figures resembling spores and fruiting organs of the fungus (grains and terminal 'heads' of the threads), it was proved that they can be obtained by precipitation of iron phosphates from a solution even in vitro. Thus, the entire body of data most probably indicates that although Aspergillus can in some exceptionally rare cases penetrate into the bloodstream and internal organs of the human body and even exist there for some time, it apparently does not cause any significant reaction and in any case has no connection with splenomegaly or with the scleropigment nodules, nor with those iron-impregnated formations that occur in them.