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 (AML) have not been established yet. This study analyzed clinical and biological characteristics, the impact on prognosis, and the cumulative incidence of EMI in a monocentric retrospective series. All adult patients diagnosed with AML observed in our institution between January 2010 and December 2017 were included in the analysis. Overall, 346 AMLs were analyzed. The incidence of EMI was 11% (38 patients). The involved sites were: skin (66%), central nervous system (CNS) (23%), pleura (7%), lymph nodes (5%), peritoneum (2%), spleen (2%), pancreas (2%), breasts (2%) and bones (2%). Most patients (91%) had only one EMI site, while 9% had multiple sites affected at the same time. Twenty-four (63%) patients showed signs of EMI at presentation, while extramedullary relapse occurred in 10 patients (26%); 4 patients had EMI both at presentation and relapse. EMI had a significantly higher frequency in patients with monocytic and myelo-monocytic leukemia subtypes (p