Clinical and prognostic features of patients with philadelphia chromosome‐positive chronic myelogenous leukemia and extramedullary disease

Twenty‐four patients who developed extramedullary disease during the course of Philadelphia chromosomepositive chronic myelogenous leukemia are described. The most frequent sites of extramedullary disease were lymph nodes (54%), bone (37%), and skin and soft tissue (29%). The appearance of extramedullary disease was associated with a high incidence of other features of accelerated disease (37%) and with cytogenetic clonal evolution (62.5%). The median time from extramedullary disease to blastic crisis was 4 months, and the median survival was 5 months. At the time of analysis, 23 patients have died, 16 after evolving into blastic crisis, and 7 from progressive disease without satisfying the criteria of medullary blastic crisis. This study confirms the importance of extramedullary disease as a sign of poor prognosis in chronic myelogenous leukemia, and the need for alternate therapies when such an event develops. Cancer 59:297–300, 1987.