It is well known that many diseases of the hemiopoietic system present cutaneous manifestations at some time during the course of their evolution. In 1876, Biesiadecki1 called attention to these changes when he reported a case of true leukemia with multiple small leukemic tumors in the skin. Cutaneous reactions occur in both general types of leukemia but are notably more common in the lymphatic variety. These visible expressions may take the form of petechiae, vesicles, papules, pustules, wheals, nodules, tumors and localized or general infiltrations. Not infrequently combinations of one or more of these forms exist, excepting the generalized form, which is thought to occur independently. In addition, there may be present pigmentary changes; and sensory disturbances, in a variable degree, may be complained of by the patient. Arndt,2 in an excellent monograph read before this section in 1914, says that he prefers to divide these manifestations into