Myeloid cells in cerebrospinal fluid.

The cells of cerebrospinal fluid are usually examined in a Fuchs-Rosenthal chamber using a nuclear stain. By this means it is possible to distinguish between polymorphonuclear leucocytes and lymphocytes, but difficulties arise when other types of cell are predominant. If films can be made of a quality comparable with that expected for haematological diagnosis, various other cell types are found. Besides neutrophil polymorphonuclears and small lymphocytes, one sees many cells of the lymphoid and plasma cell series, eosinophils, occasionally basophils, and a variety of monocytoid cells and macrophages (some of which may possibly be derived from the leptomeninges). For illustrations the reader is referred to Szecsi (1911), Rotstadt (1916), and Chalier and ttienne-Martin (1935). In rare cases tumour cells can be identified (Spriggs, 1954) or the abnormal cells of leukaemia (Spriggs and Boddington, 1958). A surprising finding, which does not appear to have been previously described, is the presence of promyelocytes, myelocytes, and normoblasts in the cerebrospinal fluid of non-leukaemic cases. There are only some very doubtful instances in the literature. For example, Szecsi's (1911) coloured drawings include some granular cells referred to in the caption as lymphoidocytes; Plaut, Rehm, and Schottmuller (1913) mentioned a case in which granular " plasma " cells were present, the granules staining red-brown with Schridde's method (aniline acid fuchsin); and Rotstadt's (1916) coloured plate shows in row IV, Cell 7, something which might be a myelocyte, interpreted as " ? Mastzelle ". We have observed four cases in which myeloid cells occurred in the cerebrospinal fluid in conditions other than leukaemia, and brief case histories are given below. The method of preparing films is given by Spriggs and Boddington (1958).