Is there a form of anæmia dependent upon hyperplasia of the bone-marrow—an anæmia medullaris? In 1875, Pepper and Tyson29 found affection of the marrow in idiopathic anæmia, and Pepper suggested that this might be the starting-point of the disease, which could thus be regarded as a medullary form of pseudo-leukæmia. Cohnheim in 187630 described the same condition, and I had an opportunity of examining several cases.31 Granting that the marrow is a tissue which shares in the blood-making functions, it seemed reasonable to suppose that a general hyperplasia of its elements might disturb the processes of hæmatosis and produce anæmia, just as in hyperplasia of the spleen and lymph-glands. Two facts soon came to light which seem opposed to this explanation of the pathology of idiopathic anæmia. A hyperplasia of the marrow was found in cases of chronic disease with wasting, and cases of idiopathic anæmia were described in which the marrow was normal. The numerous observations of the past five or six years have not brought us nearer to a solution of the problem. The observations of Neumann,32 and those of Litten and Orth,33 on the changes in the marrow in chronic diseases have been abundantly confirmed, and a red lymphoid marrow may be met with in various cachectic states. This, too, I have frequently seen, yet it is in my experience rare to find such marked, rich hyperplasia of the marrow, such an entire absence of fat, as in some cases of idiopathic anæmia. In 9 autopsies in typical cases at Montreal, not parturition cases, the marrow of the long bones was lymphoid and red in 6; in 1 it was not examined; in 1, which I did not see, the marrow was stated to be normal; and in 1, an old woman over sixty years of age, the marrow of the short bones was rich in lymphoid cells and nucleated red corpuscles, and the long bones contained a grayish gelatinoid—atrophic—marrow. It does not appear possible with our present knowledge to arrive at a satisfactory conclusion on this question. Some regard the marrow-change as the consequence, others as the cause, of the anæmia. Both Cohnheim34 and Pye-Smith35 regard those cases of idiopathic anæmia in which the marrow-changes are pronounced as cases of anæmia medullaris.
29 American Journal Med. Sciences, 1875, ii.
30 Virchow's Archiv, Bd. lxviii.
31 Centralblatt f. d. Med. Wissenschaften, 1877, Nos. 15 and 28; 1878, No. 26.
32 Berl. klin. Wochenschrift, 1877, xlvii.
33 Ibid., 1877, li.
34 Loc. cit., Bd. i. S. 467.
35 Loc cit.
Next of the parallel series of hyperplasias of the blood-forming organs with anæmia, plus an increase of the colorless corpuscles—leukæmia. Here, too, we have the three forms—splenic, lymphatic, and medullary.
The splenic leukæmia is the most common, and in its general features is identical with splenic anæmia, the excess of white corpuscles being the only distinguishing feature. It is almost invariably associated with changes in the marrow.