Histology of the Blood, Normal and Pathological

by Paul Ehrlich; Adolf Lazarus

("Mixed leucocytosis.")

In spite of the enormous extent of the hæmatological observations of the last decennia, of which a very considerable portion deals with the problem of leukæmia, the literature shews many obscurities and misconceptions, even on important fundamental ideas. This is especially the case with the weighty question of the distinction between various forms of leukæmia.

From the purely clinical standpoint it is usual to describe a lienal, a lienomedullary, and a pure medullary (myelogenic) form of leukæmia. But the distinguishing characteristics in this classification are crude and purely external, and they find no place in hæmatology.

Neumann first shewed that the lymphoid proliferation in lymphatic anæmia is not confined to the lymph glands, but may extend to the spleen and bone-marrow. These proliferative processes may give rise to a considerable enlargement, for example, of the spleen, without any change in the specific character of the leukæmia, or the condition of the blood. In spite of the splenic tumour we have to deal then with a pure lymphatic leukæmia. In customary clinical language, a case of this kind would be described as lieno-lymphatic leukæmia. The unreliability and incorrectness of this terminology is best illustrated by another form of leukæmic metastasis. In lymphatic leukæmia the liver may swell by lymphomatous growth, to a large tumour, and we ought then to speak of a "hepato-lymphatic" form of leukæmia. This term is by no means so misleading as lieno-lymphatic; for no one would conclude from the former that any liver-cells passed into the blood, whilst the latter implies the idea, that specific splenic cells take part in the blood changes.

Further, the assumption of a pure lienal variety of leukæmia is totally unwarranted from hæmatological investigations. The possibility of a specific blood change, depending solely upon disease of the spleen, appears à priori almost excluded, after what has been said on the physiological participation of the spleen in the formation of the blood.

Pathological data completely confirm this view. Ehrlich at least, in an enormous number of cases, has never once succeeded in confirming the existence of a purely splenic form from the blood examination[33].

The conditions in myelogenic leukæmia are quite similar, for foci of myeloid tissue may appear in the spleen or lymph glands according to the kind of metastasis. As it is the proliferation of the myeloid tissue and not the accompanying swelling of spleen or lymph glands that is specific in the process, the nomenclature "lienomedullary or medullary-lymphatic" leukæmia must also be described as illogical and misleading.

We distinguish then, from the histological standpoint, but two forms of leukæmia:

1. leukæmic processes with proliferation of lymphoid tissue:

"lymphatic leukæmia";