This is not the place in which to go into any minute discussion of this subject nor further than should be of practical interest to the surgeon; nevertheless an examination of the blood by some common and routine procedure is so necessary in many surgical conditions that it is impossible to entirely avoid the subject in a work like this. I have accordingly condensed it and put the salient facts about leukocytes into the following table:
Classification of Leukocytes.
| Granular. | Non-granular. | ||||||
|---|---|---|---|---|---|---|---|
| Normal. | - | Oxyphile. | A. | With fine granules | C. | Hyaline. Transitional (large | |
| Neutrophile. The so-called | (polynuclear) 60-70 per cent. | mononuclear) 4-8 per cent. | |||||
| neutral stain being | B. | With coarse granules | D. | Lymphocytes (small | |||
| slightly acid. | (eosinophiles) 2-5 per cent. | mononuclear) 20-30 per cent. | |||||
| Pathological. | - | Basophile. | E. | Fine and coarse granules | G. | Atypical hyaline | |
| (basophiles, mast-cells, etc.). | (myelocytes). | ||||||
| Oxyphile. | F. | Atypical (myelocytes). | |||||
In normal blood by far the greater part of the leukocytes consists of A and D. Lymphocytosis means a relatively high percentage of C and D. Eosinophilia means an increase in the proportion of B. Basophile cells are not absolutely pathological, for they may be present in very small numbers in normal blood.
The number of leukocytes in normal blood will average about 7000 to 10,000 per cubic millimeter, the percentage of each variety being given in the above table. Leukocytes are sometimes diminished in number; under diseased conditions they are often increased, and these are then included under the term leukocytosis. Variations occur daily and almost hourly under normal conditions. Increase naturally occurs after digestion, when the number of leukocytes may be almost doubled, the same being due principally to lymphocytes which are washed into the blood system from the lymph nodes by the flow of lymph or chyle. In starvation, however, the number may be remarkably reduced and in the case of the fasting man, Succi, the leukocytes were reduced at the end of the first week to 860 per cubic millimeter. The rather unusual condition of reduction of the number of corpuscles is called leukopenia.
Leukocytosis is usually the rule in carcinoma, with increase in A and F; the more rapid the growth, the greater this increase. In sarcoma this is even more pronounced; when occurring without hyperinosis the probability of malignancy is greater. Non-malignant tumors produce no such changes.
The blood platelets or plaques first described by Bizzozero, in 1882, have no small interest for physiologists and pathologists, but little for the practising surgeon. They number perhaps 5,000,000 per cubic millimeter and sustain a fairly constant ratio to the red cells. Their surgical interest is limited to the role which they may play in the formation of thrombus.
The term phagocytosis has to do in a general way with those leukocytes which act as scavengers by removing from the blood its noxious elements, presumably by a process of ingestion and digestion (see [Chapter III]).
Examination and estimation of the various formed elements of the blood are very valuable to the surgeon in the study of the anemias, of acute inflammation when the presence of pus is suspected, in the presence of suspected cancer, and in the presence of such conditions as Hodgkin’s disease, the various disorders of the spleen, etc. The so-called primary anemias include only the pernicious anemias and chlorosis; all others are designated as secondary. This distinction is not for convenience only, but serves a useful purpose.
Pernicious anemias produce a reduction both of the red corpuscles and the hemoglobin, the former usually in a greater degree than the latter, so that the color index (see below) is usually plus. Many of the cells become nucleated and, in general, their size is increased. In chlorosis the reduction of the hemoglobin is relatively large and the color index is extremely low. In the secondary anemias the red cells and hemoglobin are reduced disproportionately, so that the color index is minus. There may or may not be a relative increase of leukocytes and of the nucleated red cells, but these latter are not so likely to be as large as those seen in primary anemias. The color index is obtained by dividing the percentage of the hemoglobin present by the percentage of the red cells.