Hyperplasia

“ The splenic hyperplasia of leukæmia and of anæmia splenica are histologically identical. The excess of white corpuscles may be due either to over-production or to failure in their transformation into red. That they develop in the hyperplastic spleen, marrow, and lymph-glands is not to be doubted, and it seems reasonable to attribute the excess to the hyperplasia. Their variable size, as spleen or lymph-glands are chiefly affected, was early observed by Virchow, and when the marrow is involved there may be many large leucocytes similar to the larger marrow-cells. ”

“ A chronic, progressive, hyperplastic-degeneration exists in some cases and the subjects are in time rendered unserviceable because of the burden of getting about encumbered by the affected extremity. In other animals hyperplasia progresses for a time—until the parts become greatly enlarged and conditions apparently attain an immutable state. ”

“ Similar adenoid hyperplasia has been found in the lungs, the bronchial mucous membrane, the pleura, the mediastinal and bronchial glands, and the pericardium. In man this has invaded the nerve centres, and it seems that at any point where there is a lymph gland or a lymph plexus this adenoid hyperplasia may localize itself.
Symptoms. The general symptoms of failing health are as described in leukæmia. The particular symptoms of this disease consist in the recognition of the adenoid hyperplasia in the absence of a marked leucocytosis. ”

“ The sternum and ribs are most frequently affected in this way. There are instances in which the bone-marrow has not been involved, and in one case there was osteo-sclerosis.135 Histologically, the chief change is hyperplasia of the colorless marrow-cells, which in the pyoid variety compose the chief part of the tissue. They vary much in size and appearance. Three forms can usually be recognized: large granular cells with distinct nuclei; medium-sized cells, like colorless blood-corpuscles; and smaller forms, like lymph-cells, with large nuclei and a narrow zone of investing protoplasm. ”

“ In a case of Eve’s the facial hypertrophy extended to the brain.
In the ordinary forms of congenital hypertrophy [138] the size of the part is augmented by an unequally distributed hyperplasia of the skeleton and soft parts. Almost all the cases narrated in detail are of this kind. In nearly all, the arterial supply is proportionate only to the normal size of the part, and the functional capacity (power, sensibility, &c.) , although not seriously altered, is to some extent deteriorated. ”

“ Occasionally, gestation, parturition, the puerperium, and lactation seem to exercise a favorable influence on the state of the parenchyma. In exceptional cases all traces of the original chronic metritis disappear with the puerperium. The connective-tissue hyperplasia may undergo the same involution to which the hypertrophied muscular tissue is subject. This favorable termination of the disease is seldom observed during the stage of induration. ”

“ The anatomical lesions of chronic interstitial hepatitis consist essentially in hyperplasia and hypertrophy of the connective tissue of the organ. The progress of the affection is insidious and gradual; some degree of enlargement, due in part to congestion and in part to interstitial exudation, is followed by gradual diminution, with retraction of the new connective tissue. ”

“ In follicular goitre there is a proliferation, both in the cell-elements of the follicles and in the connective tissue constituting their walls. This general hyperplasia of the normal histological components of the gland constitutes a tumor which, for a time at least, remains quite soft and compressible, even communicating to the touch the sensation of fluctuation. The tendency, however, of the growth is not to remain long in this condition, but to become more firm and even hard to the feel. ”

“ According to some observers, it is to the proliferation of the proper gland-cells that the new formations owe their origin; according to others, to the hyperplasia of the cells lining the ducts. As the growth of the new formation can take place only through an adequate blood-supply, it becomes very important to ascertain its source. There can be little doubt that primary cancer of the liver receives its nutrient supply through the hepatic artery, in connection with which new capillaries form in the pathological tissue. ”

“ The spleen is usually enlarged—often, indeed, to twice its natural size. The liver presents highly-characteristic alterations. When death occurs early the organ is generally enlarged, infiltrated with fat, the connective tissue undergoing hyperplasia; but in more advanced cases atrophy has taken place, the cells have disappeared and are replaced by fat-granules, crystals of leucin and tyrosin, connective tissue, etc.—in fact, the changes characteristic of acute yellow atrophy. ”

“ The contraction and shrinking of the fibroid hyperplasia as the disease advances causes the projection of the hepatic tissue in minute rounded elevations which give a peculiar uneven appearance to the surface of the organ. The fibroid growth gives a remarkable hardness to the liver which resists even the edge of a knife. The hepatic cells are the seat of fatty and pigmentary degeneration. Inflammation and tumefaction of the kidneys, and ascites are common features of the malady.
Symptoms. The general symptoms are as in parenchymatous hepatitis with a more tardy development. ”

“ Newly-affected glands may be found alongside of others in an advanced condition. In the first stage the glands are enlarged, but rarely exceeding the size of a filbert; they are firm, but not inelastic. This change consists in hyperplasia of the gland-constituents. Microscopic examination shows abundant cell-proliferation, but the cells are badly constructed and prone to undergo retrogressive metamorphosis. The cells accumulate in clusters without any intercellular substance, and compress the lymph-sinuses and blood-vessels. ”

“ Early and rapid growth in the mediastinal groups may produce pressure effects, and cause death before any marked anæmia—much less cachexia or the development of secondary masses in important organs, as the cord, may prove quickly fatal. In some cases the glandular enlargement rapidly spreads, and group after group is involved in the space of a few months; in others there may be hyperplasia of a single set, as the cervical on one side, for months, or even years, before the glands on the other side or in other regions become involved. ”

“ In the spleen the pulp at first increases and the Malpighian bodies enlarge, but ultimately there is such a development of the fibrous reticulum that the consistence is greatly augmented and the organ becomes indurated. Histologically, there is very little distinction to be made between forms of chronic enlargement of this organ. In the lymph-glands there is increase in the cells; the tissue becomes more succulent, and is in a state of hyperplasia which may terminate in a great development of the fibrous elements, with induration. ”

“ Enlargement of the spleen from simple hyperplasia must also be distinguished from other forms of splenic enlargement—from splenitis, from lardaceous degeneration, from tumors, from leukæmia and pseudo-leukæmia, from syphilitic and tuberculous [p. 959] spleen, etc. In such cases the diagnosis will rather depend upon concomitant symptoms than upon the physical characters of the enlarged organ. Percussion and palpation will not seldom enable one to determine the presence of tumor (cancer) , hydatids, etc. Pressure will often serve to elicit expressions of great tenderness in splenitis ”

“ The process of division goes on in the blood in such a manner that the nuclear rod first divides into two to four single nuclei, and then the whole cell splits up into as many fragments. These cells occur also in fresh pleuritic exudations. After a time the nucleus of these cells becomes free, and the little masses of protoplasm thus cut off are taken up mostly by the spleen substance. The free nucleus likewise shares in the destruction. It is of the greatest importance that these cells, which up to the present have not elsewhere been described, should receive more attention. ”

“ The process consists in the proliferation of epithelial cells from the mucous layer. The cell-growth takes place downward in the form of finger-like prolongations or columns, or it may spread out laterally, so as to form rounded masses, the centres of which usually undergo horny transformation, resulting in onion-like bodies, the so-called cell-nests or globes. The rapid cell-growth requires increased nutriment, and hence the blood-vessels become enlarged; moreover, the pressure of the cell-masses gives rise to irritation and inflammation, with corresponding serous and round-cell infiltration. ”

“ It is curious that the majority of cases are males, and that it is transmitted by women who are not themselves its subjects. Many different clinical types have been described based upon the age of onset, the groups of muscles first affected, and the presence or absence of apparent hypertrophy; they are however all varieties of one affection, and in a case where there is an apparent enlargement of muscles there is really atrophy of the contractile muscle, fibres and overgrowth of fat and interstitial fibrous tissue; consequently this form of the disease is called pseudo-kypertrophic paralysis. ”

“ Its nucleus is large, stains rather palely, has a delicate chromatin network, and often shows evidences of degeneration (karyorrhexis, etc.) . In ordinary work, however, it is safer to base the distinction upon size than upon structure. Any nucleated red cell, but especially the megaloblast, may exhibit polychromatophilia.
Normally, erythroblasts are present only in the blood of the fetus and of very young infants. Pathologically, normoblasts occur in severe symptomatic anemia, leukemia, and pernicious anemia. ”

“ It is of equal, if not greater, importance to bear in mind the organ concerned.
In the heart, liver, kidneys, and gastric glands, as well as elsewhere, with the exception, perhaps, of the mammary gland, the presence of many small fat-drops in the cells indicates a degeneration of its protoplasm. The presence of large fat-drops, on the contrary, in the organs and tissues, with the exception of the liver, indicates an infiltration. Large fat-drops, then, may be present in the cells of the liver as the result of an infiltration or of a degeneration. ”

“ If the demand be for the red cells owing to loss from hemorrhage or any of the anaemias, the fatty marrow is rapidly replaced by cellular elements; this is mainly an active proliferation of the nucleated red cells, and gives rise to the erythroblastic type of marrow. If the white cells be required, as in local suppurating abscess, general septicaemia, acute pneumonia, &c., there is an active proliferation of the myelocytes to form the polymorpho-nuclear leukocytes, so that we have in this condition a leucoblastic transformation of the fatty marrow. ”

“ Hypertrophy—Enlargement of the Heart Definition.—An abnormal growth of the muscular tissue of the heart by thickening of the walls.
Varieties.—There are three. Simple Hypertrophy is the thickening of the walls without any change in the capacity of the cavities. Eccentric Hypertrophy is the thickening of the walls with dilatation of the cavities. Concentric Hypertrophy is the thickening of the walls with diminution of the cavities. The lesion is usually associated with other diseases, and especially with affections of the lungs. ”

“ New formation of cells goes on with great rapidity in intra-uterine life, the child, beginning its existence as a single cell one two hundred and fiftieth of an inch in diameter, attains in nine months a weight of seven pounds. The only similar rapidity of cell formation is seen in certain tumors; although the body may add a greater amount of weight and in a shorter time, by deposit of fat, this in but slight measure represents a new formation of tissue, but is merely a storage of food material in cells. ”

“ The erythroblasts continue to multiply by karyokinesis in early foetal life, especially in the liver, spleen, bone marrow and lymphatic glands, though later on their formation only occurs in the red bone marrow. In most of the erythroblasts the nucleus soon becomes contracted, and the cell is then known as a normoblast, while ultimately the general view is that the nucleus disappears by extrusion from the cell and the non-nucleated red blood plates or erythrocytes remain. ”

“ The relative amount of fibrous stroma and cells determines the consistency of the mass, and whether it approximates to the hard cancer or the soft. In the horse’s liver they are usually hard, and, on scraping off the cut surface, yield only a limited quantity of cancer juice. In the epithelial form, which embraces nearly all that have originated from primary malignant growth in the walls of the intestine, the epithelioid cells, flattened, cubical, polyhedral, etc., are arranged in spheroidal masses or cylindrical extensions, which infiltrate the tissues more or less. ”

“ The concentric variety of growth includes those tumors which have commonly been described as encapsulated, and which are capable of ready enucleation from their surroundings in virtue of a thin layer of loose connective tissue lying between the tumor and the contiguous tissue. Such a capsule represents the matrix, the pia mater, in which lie the blood-vessels going to and coming from the tumor, and is often nothing else than the distended and hyperplastic fibrous tissue remaining after the absorption of the muscular fibres or gland-cells from the tissues surrounding the morbid growth. ”

“ When the cells are destroyed, their remains may be discerned in the mass of connective tissue as fine fat-granules or masses of pigment yellowish or brownish in color. The peculiar appearance to which the name cirrhosis is applied is due to the lobules or groups of lobules which project on section above the divided surface, and are colored yellowish by the bile-pigment, which here exists in an exaggerated quantity. The cells themselves are not normal: they are enlarged by compensatory hypertrophy, and they contain much bile-pigment and a considerable quantity of fat. ”