The tonsils and the lymph-follicles of the tongue, pharynx, and mouth have been found much enlarged.
The bone-marrow is usually the seat of important changes, which in some cases appear early and persist as very prominent features of the disease. The most constant alteration is a uniform substitution of a grayish-red or gray-green puriform-looking tissue for the normal red and fatty marrow of the long and short bones. The entire medulla may resemble the consistent matter which forms the core of an abscess, and the term pyoid applied to this condition by German authors well expresses the general characters. More rarely the marrow has a reddish-brown hue. The difference depends largely on the number of colorless corpuscles, which in the pyoid form are enormously increased, and there are but few red cells. Ponfick has met with dark-red, dense hemorrhagic infarctions in leukæmic marrow. The condition of the bones is variable; usually, the compact and cancellated tissues appear normal, but the hard shell may be much thinned and expanded, the cancellæ widened, and the whole substance rendered spongy. In marked cases there may be localized swellings which are tender, and even yield, on firm pressure. 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. The red corpuscles and microcytes are in variable numbers. In one case the latter were very abundant. Nucleated red corpuscles are very constant elements. Corpuscles containing red blood-corpuscles are not so numerous as in ordinary red marrow, nor, as a rule, are the myeloplaques abundant. Charcot's crystals are always to be found—if not at first, when the marrow is quite fresh, certainly later, when decomposition has begun.
135 Heuck, Virchow's Archiv, lxxviii.
The thymus is rarely affected, and even in children is not often swollen. A few cases of enlargement have been recorded.
The thyroid is even less frequently involved.
In one case the suprarenal capsules were large and swollen,136 and in addition to the leukæmia there was bronzed skin. Hemorrhage, caseous degeneration, and in one instance rupture,137 have been noted.
136 Barclay, Lancet, 1863, i.
137 Fleischer and Penzoldt, loc. cit.
In the digestive system the stomach rarely presents any changes other than catarrhal. Even when death has occurred from hæmatemesis the mucous membrane may be pale, without erosion, hemorrhage, or ulceration (Cases II. and VI.). In a few instances lymphatic growths have been described. In many cases the intestines have been the seat of leukæmic tumors which have originated in the solitary and agminated glands of Peyer. Occasionally the lymphoid infiltration is diffuse in the mucosa and not confined to the follicles. Ulceration may occur in the patches, and in a few cases the bowel lesions have been so pronounced that the term intestinal leukæmia seemed justifiable.138 The cæcum and colon may also present these new growths, and in a few cases dysenteric processes have been observed (Case II.). The peritoneum has been found covered with small lymphoid growths. In Willcocks' case of lymphatic leukæmia139 there were growths on the surface of the stomach and gastro-splenic omentum. Blood may be found in the cavity from rupture of the spleen. Ascitic fluid is common. Fibroid thickening, induration, and adhesions are very often met with, particularly in the neighborhood of the spleen.
138 Behier, loc. cit.