The predictive value of morphological findings in early diagnosis of acute myeloid leukemia with recurrent cytogenetic abnormalities

Abstract

This study explores cytomorphologic features and their predictive role for early identification of acute myeloid leukemia (AML) with morphological distinctive recurrent cytogenetic abnormalities (RCA): t(15;17), t(8;21) and inv(16)/t(16;16). We retrospectively evaluated 396 de novo AML cases, diagnosed and treated at single institution, between 2013-2017. Specific cytomorphologic features suggesting distinctive AML-RCA were revealed at diagnosis in 62 (15.65%) patients, including AML with t(15;17) in 41 (66.13%), t(8;21) in 13 (20.97%) and inv(16)/t(16;16) in 8 (12.90%). Final diagnoses of AML-RCA according to WHO integrated diagnostic criteria were established in 66 (16.66%) cases, including AML with t(15;17) 40 (60.60%), t(8;21) 17 (25.76%), and inv(16)/t(16;16) 9 (13.64%). Discordance between cytomorphological and other integrated criteria was detected as missed/wrong-call in 0/1 for t(15;17), 6/2 for t(8;21) and 2/1 for inv(16)/t(16;16). The cytomorphological accuracy was 97.56% (40/41) for t(15;17), 57.89% (11/19) for t(8;21) and 70% (7/10) for inv (16)/t(16;16). Positive/negative predictive values of cytomorphological evaluation were: 97.56%/100% for t(15;17); 84.62%/88.68% for t(8;21); 87.50%/96.65% for inv(16)/t(16;16). Sensitivity/specificity were: 100%/96.15% for t(15;17); 64.10%/95.92% for t(8;21); 77.78%/98.25% for inv(16)/t(16;16). We confirmed that morphology is still a highly relevant evaluation method in diagnosing several common AML-RCAs before completing cytogenetic and molecular studies, enabling early detection, particularly of AML with t(15;17).

Keywords: Acute myeloid leukemia; Cytomorphological characteristics; Recurrent cytogenetic abnormalities; WHO classification.