Specific chromosomal abnormalities in ALL and AML

• ALL

  • 90% have chromosome abnormalities

  • Hyperdiploidy (> 50 chromosomes) is associated with a good prognosis and is fairly common in early precursor B cell ALL and in about 25-30% of all cases of ALL

  • All translocations are associated with a poor prognosis

    • 20-25% of pre-B cell ALL have a t(1;19) translocation

    • B cell ALL (ALL L3) is almost always associated with the t(8;14) translocation of Burkitt’s

• AML

  • t(9;22), the Philadelphia (Ph¹) chromosome

    • 10-15% of M1

    • Poor prognosis because of Bcr-c-abl fusion

  • t(8;21) – 20-25% M2, favorable prognosis, more in young males

  • t(15;17) – 100% M3 only; intermediate prognosis

  • Inv 16 or del 16q

    • 20-25% of M4

    • Favorable prognosis (worry about CNS involvement)

  • Del 11q or t(11,V*)

    • 30-40% of M5 (some M4)

    • Very poor prognosis

  • Trisomy 8

    • Seen in M1, M2, M4, M5, and M6

    • No prognostic value

    • Most common abnormality in a wide variety of hematopoietic neoplasms

  • Monosomy 7 or del 7q; monosomy 5 or del 5q

    • Most often in secondary leukemias, usually in people > 60YOA

    • Associated with exposure to environmental carcinogens; poor prognosis

Category: Medical Subject Notes , Pathology Notes