[Morphology and monocytopoesis of mycosis fungoides]

Nature and nosology of mycosis fungoides have to be reconsidered because there is now evidence of the t-cell nature of the atypical lymphoid cells within the mycoside infiltrate. Therefore the concept of the reticulum cells in the pathogenesis of mycosis fungoides must be corrected. On the ground of morphological and immunological reasons these cells do not exist in the dermis at all. These new findings are the basis of our morphological study in patients with mycosis fungoides. Concentrating on the polymorphous lymphohistiocytic cells, which cannot be classified further by the method of paraffin-thin sections, light microscopically, the exact differentiation is only possible with semi-thin-sections. With this technique there can be made visible the typical features of nuclei of mycosis fungoides cells. The mycosis fungoides cells are characterized by a large nucleus with hyperconvoluted nuclear membranes, prominent nucleoli, irregular distribution of heterochromatin and sparse cytoplasma. The monocytopoiesis, scheduled by the relative number and the 3H-thymidine labeling indices of promonocytes and the activity of naphthol-AS-D-chloroacetate esterase in blood monocytes was markedly increased. These findings are of special interest, because macrophages are not only able to phagocyte but also play a crucial role in immunology. The elevated monocytopoiesis in all stages of mycosis fungoides points to a stimulation of the immunologic system. This supports the hypothesis of a persistent antigen, which stimulates by means of the functional intact monocyte-macrophage system the lymphocyte system leading to a permanent transformation with augmentation of these immunoblasts (mycosis fungoides cells).