In childhood ALL, an extra chromosome 5 is commonly encountered in cases with hyperdiploidy >50 chromosomes. The presence of trisomy 5 in high hyperdiploid childhood ALL is associated with a less favourable clinical outcome. Trisomy 5 as a sole abnormality in ALL is exceedingly rare and described in only 3 cases, including 2 adult ALL and 1 paediatrics case occurring in a 12-year old girl. Tris...
