On the influence of stilbamidine upon myeloma cells.

By I. SNAPPER, M.D., AND B. SCHNEID, M.D. U NE of us’ has reported that in certain cases of multiple myeloma, considerable improvement of the clinical condition can be obtained by intravenous or intramuscular injections of stilbamidine (diamidino-stilbene di isethionate).* It is necessary that the patient follow a diet low in animal protein. A favorable result has been observed in 9 out of io patients. During this treatment with stilbamidine, histological changes can be observed developing in the myeloma cells. The basophilic cytoplasm of myeloma cells is usually vacuolated and, on the whole, is free of granules or other inclusions. From time to time a few azurophilic granules and tiny azurophilic rods, resembling Aucr bodies, are found. Exceptionally these azurophilic inclusions grow to a larger size. During a course of injections of stilbamidine large basophilic granules appear in the cytoplasm of the myeloma cells which are without difficulty visualized in hone marrow smears by Wright or Giemsa stains. These granules have first been observed after the treatment has lasted to 4 weeks. The amount of stilbamidine administered up to the time when the granules appear has varied between 1875 and 3600 mg. In the beginning the granules have a faint resemblance to swollen cocci. When the treatment is continued the granules become confluent, so that after several weeks of treatment large deeply blue precipitates, resembling inclusion bodies, are found in the cytoplasm of most myeloma cells (fig. i). Supravital staining of the myeloma cells of untreated myeloma cases with Janus green and neutral red reveals the presence ofa considerable number ofgreen staining mitochondria. In the myeloma cells of myeloma cases treated with stilbamidine the cytoplasm contains not only green mitochondria but also large red globules. Although it cannot be proved that these red granules visualized by the vital stain are identical with the blue granules found in the Wright stain, it may be stressed that both types of granules develop at the same time. The cytoplasm ofmyeloma cells stains deeply red with pyronine if Unna’s phenol methylgreen pyronine stain is used. In the cytoplasm of the untreated myeloma cases this stain does not reveal the presence ofany granules. In the patients in whom stilbamidine treatment has given rise to the development of the granules mentioned above, the Unna stain shows the presence of bright red granules in the red cytoplasm. The granules which develop in the myeloma cells under influence of the stilbamidine treatment are not metachromatic because they do not stain with Unna’s polychrome methylene blue. The granules do not show positive oxydase reactions. In 7 out of 9 cases of multiple myeloma treated with stilbamidine, these inclusion bodies were consistently present and could be found in 8o to 90 per cent of the myeloma cells of the bone marrow. In none of the other bone marrow elements