Acute myeloid leukemia in children: the study of clinical and biological features and results of the treatment at the Department of pediatrics, Clinical Hospital Centre Rijeka

Cilj: Ispitati kliničke i biološke (citomorfologija, imunofenotipizacija, citogenetika) značajke te stopu preživljenja pedijatrijskih bolesnika s akutnom mijeloičnom leukemijom (AML) liječenih u tercijarnom centru. Ispitanici i Metode: Epidemiološko, retrospektivno, deskriptivno istraživanje u koje su uključeni bolesnici s novodijagnosticiranom AML mlađi od 18 godina, u razdoblju od 01.01.2002. do 31.12.2013. godine. Rezultati: U dvanaestogodišnjem razdoblju je hospitalizirano devetero djece s AML, 5 (55,6%) djevojčica i 4 (44,4%) dječaka. Prosječna dob je bila 11 (± 3,8 SD) godina. Najčešći simptomi i znaci su bili astenija (66,7%), perzistentna vrućica (55,6%), bljedoća (44,4%) i krvarenje (44,4%). Limfadenopatija i hepatomegalija su bile prisutne u 3 (33,3%), a splenomegalija u jednog (11,1%) bolesnika. Jedan (11,1%) bolesnik je imao inicijalno zahvaćen centralni nervni sustav. Trombocitopenija je bila prisutna u 8 (88,9%) bolesnika, anemija u 7 (77,8%) bolesnika, leukocitoza u 4 (44,5%) bolesnika, a leukopenija u 3 (33,3%) bolesnika. Svi bolesnici su imali blaste u razmazu periferne krvi. Utvrđeno je 7 citomorfoloških podtipova s karakterističnim imunofenotipskim značajkama. Sedam (77,8%) bolesnika je imalo numeričke i strukturne aberacije kromosoma. Tri (33,3%) bolesnika su svrstana u grupu standardnog rizika, a 6 (66,7%) u grupu visokog rizika. Remisija je postignuta petnaestog dana kemoterapije u 6 (66,7 %) bolesnika. Alogena transplantacija krvotvornih matičnih stanica je učinjena u 3 (33,3%) bolesnika. Osam (88,9%) bolesnika je u kompletnoj remisiji s medijanom praćenja od 10,1 godina. Smrtni ishod je nastupio u 1 (11,1%) bolesnika uslijed septičkog šoka. Zaključci: Pedijatrijska AML je heterogena hematološka neoplazma. Agresivna kemoterapija i transplantacija krvotvornih matičnih stanica omogućuju visoku stopu izlječenja.Objective: To investigate clinical and biological (cytomorphology, immunophenotyping, cytogenetics) features and the survival rate of pediatric patients with acute myeloid leukemia (AML) in a tertiary centre. Material and Methods: Epidemiological, retrospective, descriptive study involving patients with newly diagnosed AML younger than 18 years, from January 1st 2002 to December 31st 2013. Results: In a 12-year period, 9 children with AML were hospitalized, 5 (55.6%) girls and 4 (44.4%) boys. The median age was 11 (± 3.8 SD) years. The most common symptoms were asthenia (66.7%), persistent fever (55.6%), pallor (44.4%) and bleeding (44.4%). Lymphadenopathy and hepatomegaly were present in 3 patients (33.3%), and splenomegaly in one (11.1%) patient. One (11.1%) patient had initial central nervous system involvement. Thrombocytopenia was present in 8 (88.9%) patients, anemia in 7 (77.8%) patients, leukocytosis in 4 (44.5%) patients, and leukopenia in 3 (33.3%) patients. All patients had blasts in the peripheral blood smear. Seven cytomorphologic subtypes with characteristic immunophenotypic features were found. Seven (77.8%) patients had numeric and structural chromosome aberrations. Three (33.3%) patients were classified in standard-risk group and 6 (66.7%) in high-risk group. Remission was achieved in 6 (66.7%) patients on day 15 of chemotherapy. Allogeneic hematopoietic stem cell transplantation was performed in 3 (33.3%) patients. Eight (88.9%) patients are in complete remission with a median follow-up of 10.1 years. The death occurred in one (11.1%) patient due to septic shock. Conclusions: Pediatric AML is a heterogeneous hematologic neoplasm. Aggressive chemotherapy and hematopoietic stem cell transplantation provide a high cure rate