MICROSCOPIC PATHOLOGY
Skin.—As pointed out by Aschoff and Koch, examination of skin which to gross appearance was the seat of typical small hemorrhages, showed various lesions. In some, perhaps the most typical forms, there had been a fresh extravasation of red blood-cells. This condition is found usually in the subepidermal layers, especially in the papillary stratum. These small hemorrhages occur very frequently about the hair follicles and sweat glands, especially when they have been diseased. Where the bleeding has been of long standing, dark brownish pigment deposits are found and all blood-cells may have disappeared. Phagocytic cells are almost always present and may be of the “wandering” or of the more fixed connective-tissue type. Many round cells may be seen in these areas lying between the connective-tissue strands or around the blood-vessels. Rheindorf, as quoted by Tuechler, has called attention to this round-celled reaction, which in many instances gives a picture analogous to the granulomas, and which leads him to infer an infectious origin for these lesions. Other areas which appeared to be the seat of hemorrhage are shown by the microscope to be small abscesses or new connective tissue often loaded with pigment and detritus, apparently representing the final stage of these lesions. Aschoff and Koch have found that suitably-stained preparations frequently show a loss of elastic fibres, which Rheindorf states constitutes one of the earliest changes of this disorder. The blood-vessels in the vicinity of the hemorrhages are congested, especially the capillaries and small venules.
The muscles also present a similar diverse picture of old and recent hemorrhages, pigment deposit and round-celled infiltration. Increase of connective tissue is usually found between the fibre bundles and in some cases where the hemorrhages are apparently of long standing, as evidenced by loss of contour of the red cells and pigmentation of the surrounding areas, this scar tissue formation is very marked. Changes in the muscle fibres themselves have not been encountered by all observers. Hayem describes widespread fatty degeneration and a deposit of pigment within the fibres, Leven a loss of sarcolemma, while Lasèque and Legroux found fatty changes which were equally marked in muscles showing no hemorrhage. On the other hand, Aschoff and Koch, in their careful studies, did not find noteworthy fatty change of the fibres, but observed often that the fibres within the hemorrhagic areas seemed shrunken and were stained abnormally deep with eosin.
In monkeys dying of experimental scurvy, Hart and Lessing describe granules in the muscles, which, judged by their staining affinities, evidently contained calcium and were similar to those found in the adrenal glands.
Blood-vessels.—A similar difference of opinion obtains in regard to the changes in the walls of the blood-vessels, especially of those in hemorrhagic areas. This question is of particular interest because of its bearing on the problem of the mechanism involved in the escape of the blood. Since it has been demonstrated that neither the clotting time nor the viscosity of the blood is markedly changed in scurvy but that weakness of the vessel walls exists, as demonstrated by “the capillary resistance test,” it is natural that we should seek an explanation in the microscopic pathology of the vessels. So far no change has been found. The application of some of the newer stains, such as those for mitochondria and other cell granules, has not been resorted to for this study, and might furnish valuable information.
Hayem found fatty infiltration of the walls of the small veins and capillaries, and believed this to play an important rôle in the etiology of these bleedings. Lasèque and Legroux also found occasional fatty changes. Other authors have failed to demonstrate similar lesions, or have considered them due to postmortem change. Koch searched in vain for “rents” in the vessel walls to account for the escape of blood. Hyaline degeneration has also been described, but is believed to result from secondary infections and not to be an intrinsic lesion of scurvy (Sato and Nambu, Aschoff and Koch).
Thrombosis of vessels is found both in the neighborhood of hemorrhage and elsewhere, the thrombi at times completely occluding the vessels and giving rise to typical wedge-shaped infarcts. The lung often shows areas of this kind.
Lungs.—Hemorrhages of various size occur in the tissue of the lung or in the air spaces. Hemorrhagic infarcts also have been described, and Sato and Nambu report hyaline degeneration of the blood-vessel walls. Secondary pneumonias, usually broncho-pneumonic in type, are of common occurrence, and in many epidemics constitute the prevailing cause of death. Tuberculous lesions are also frequently present, and are stated to assume fresh activity as the result of the nutritional disorder. Edema occurs frequently, the fluid in the acini often containing red blood-cells. Subpleural hemorrhages, thickening of the pleura, purulent or fibrinous pleurisy are common lesions.
Heart.—Although hypertrophy and dilatation of the heart have been noted by several observers, microscopic changes have rarely been recorded. Meyer, and also Leven, report fatty degeneration of the muscle fibres, which, however, was found by Aschoff and Koch in only one case. Sato and Nambu described an increase of connective tissue, and others anemia and pigmentation. Thickening of the pericardium and subserous hemorrhages also occur.