4th. Diminished nutritive activity of all those processes, both physiological and pathological, which depend upon a full supply of nutritive blood.
The most striking feature in all scrofulous inflammation is excessive cell-growth, but these cells show little tendency to differentiation and organization, probably for two reasons: 1st, because they are derived from the blood-vessels principally, and not from proliferation of the proper connective-tissue cells of the part; and 2d, because they are insufficiently supplied with nutrition from the scanty blood-vascular network, and this supply is too rapidly absorbed into the lymph-spaces, and is carried off by the too numerous lymph-vessels. The cells, therefore, speedily perish, undergo partial or imperfect fatty degeneration, and finally caseation, unless the process is going on at a free surface, in which case, of course, they are shed and thus gotten rid of.
Virchow some time ago called attention to the predominant cellular character of the scrofulous exudation and the low vitality of the cells which compose it. Rindfleisch declares that the fresh scrofulous exudations contain relatively large cells with glistening protoplasm, and that the white blood-corpuscles have a tendency in scrofulous persons to grow larger on their way through the connective tissue. He adds that they swell up by the imbibition of albuminous substances, and by this very swelling die and slowly degenerate.
It seems to the writer, however, that it is probable that herein lies the reason why swelling and apparent hyperplasia of the lymphatic glands in the neighborhood of a local inflammation occurring in a scrofulous person always takes place. The swollen cells become arrested at the first gland they reach, and block the channels through the gland. Successive additions of cells continue to block these channels, and finally the passage of lymph through the gland becomes impossible, and then begins that secondary increase of the lymph-cells in the gland resulting from their inflammatory proliferation.
"In scrofulous inflammation," say Cornil and Ranvier,7 "there is a remarkable tendency to permanent infiltration of the affected tissue. In simple inflammation (i.e. inflammation in non-scrofulous persons) the infiltration is a temporary condition which terminates in suppuration, in organization, or in resolution." Now, the several steps in this process of resolution are—contraction of the distended blood-vessels, thus cutting off the excessive supply of blood which has caused the exudation and cell-proliferation; fatty degeneration of the new cell-formation; liquefaction of this fat by union with the alkaline blood-plasma, converting it into a dialyzable (saponaceous) liquid which can now be readily absorbed by the veins. In scrofulous infiltration the cells are speedily attacked by fatty degeneration (which seems to be strictly a physiological process), but instead of becoming liquefied, it (the fat) remains, slowly dries and hardens, and finally becomes converted into the so-called cheesy mass or cheesy infiltration. It does not liquefy, because it does not receive a sufficiently abundant supply of the alkaline blood-plasma from the scanty blood-vessels, and that which is supplied too rapidly flows into the numerous large lymph-spaces and is carried off by the lymph-vessels. In the case of the infiltrated gland the supply of this plasma is cut off in both directions. The passage of lymph through the gland is blocked, when, of course, none can then reach it through the lymph-vessel leading to it, while the swelling of the gland itself from accumulated cells compresses the neighboring nutrient vessels and cuts off the supply from this direction also. Hence the speedy death, fatty degeneration, and caseation (not liquefaction) of the cells.
7 Ed. 1880, p. 114.
"The newly-formed material not only interrupts the lymph-passages of the gland, but also compresses the blood-capillaries in such manner that the circulation completely stagnates. It is impossible by any method of injection to penetrate into the most swollen parts of the gland. With the supply of blood the nutrition also self-evidently ceases; the gland falls into caseous degeneration. Where this enters in the gray mass first becomes opaque, then whitish-yellow, non-transparent, dry, friable. If the whole gland has passed into the caseous condition, it appears upon a section as a fresh potato, only not quite so moist, but just as homogenously yellowish-white."8
8 Rindfleisch, Textbook of Pathological Histology, 1870, p. 202.
The subsequent fate of these glands seems to depend somewhat upon their situation. In the mesenteric and bronchial glands almost always the caseous mass is attacked by calcareous infiltration, and finally dries into a solid chalky concretion. The writer counted seven of these chalky masses around the primary bronchi of a boy about fifteen years old whose body was brought into a dissecting-room in Baltimore City. But the more common result of the caseous process in the glands of the neck is softening. "The caseous dépôt melts from within outward into a whitish-yellow, whey-like fluid, which holds a fatty granular detritus suspended in smaller or larger fragments. If all the caseous material has softened, the neighborhood of the gland is wont to inflame; this inflammation facilitates the way for the scrofulous pus outward. This is evacuated, and we have the scrofulous ulcer, with its overhanging, bluish, hyperæmic, flabby edges. At length this opening also closes, and a drawn-in, radiated cicatrix marks the place where the evacuation took place."9
9 Ibid., loc. cit.