EXTRAMEDULLARY INVOLVEMENT IN ACUTE MYELOID LEUKEMIA. A SINGLE CENTER TEN YEARS EXPERIENCE

The incidence, risk factors and prognostic significance of extramedullary involvement (EMI) in adult patients with acute myeloid leukemia have not been established yet. This study analyzed the clinical and biological characteristics, the impact on prognosis and the cumulative incidence of EMI in a monocentric retrospective study. All consecutive adult pts with a diagnosis of AML observed in our institution between January 2010 and December 2017 were included into the analysis. Overall 346 AMLs were analyzed. The incidence of EMI was 11% (38 pts). The involved sites were: skin (66%), CNS (23%), pleura (7%), lymph nodes (5%), peritoneum (2%), spleen (2%), pancreas (2%), breasts (2%) and bones (2%). Most pts (91%) had only one site of EMI, while 9% had multiple sites affected at the same time. Twenty-four (55%) patients showed signs of EMI at presentation, while extramedullary relapse occurred in 9 pts (24%); 5 pts had EMI both at presentation and at relapse. EMI had a significantly higher frequency in pts with monocytic and myelo-monocytic leukemia subtypes (p