Masked hypodiploidy: hypodiploid acute lymphoblastic leukemia (ALL) mimicking hyperdiploid ALL in children: A report from the Children's Oncology Group

Publication date: Available online 30 July 2019Source: Cancer GeneticsAuthor(s): Andrew J Carroll, Mary Shago, Fady M Mikhail, Susana C Raimondi, Betsy A Hirsch, Mignon L Loh, Elizabeth A Raetz, Michael J Borowitz, Brent L Wood, Kelly W Maloney, Leonard A Mattano, Eric C Larsen, Julie Gastier-Foster, Eileen Stonerock, Denise Ell, Samir Kahwash, Meenakshi Devidas, Richard C Harvey, I-Ming L Chen, Cheryl L WillmanAbstractHyperdiploidy with greater than 50 chromosomes is usually associated with favorable prognosis in pediatric acute lymphoblastic leukemia (ALL), whereas hypodiploidy with ≤43 chromosomes is associated with extremely poor prognosis. Sometimes, hypodiploidy is “masked” and patients do not have a karyotypically visible clone with ≤43 chromosomes. Instead, their abnormal karyotypes contain 50–78 or more chromosomes from doubling of previously hypodiploid cells. When the hypodiploid and doubled hyperdiploid clones are both present, patients can be identified by traditional test methods [karyotype, DNA Index (DI), fluorescence in situ hybridization (FISH)], but the incidence of masked hypodiploid cases in which only the doubled clone is visible is unknown. We analyzed 7013 patients with B-ALL enrolled in COG AALL03B1 (2003–2011) for whom chromosome studies were available. Of 115 patients with hypodiploidy (25-39 chromosomes), karyotypes of 40 showed only the hypodiploid clone, 47 showed mosaicism with both hypodiploid and hyperdiploid (doubled) karyotypes, ...
Source: Cancer Genetics - Category: Cancer & Oncology Source Type: research