The chronic myeloid leukaemias: guidelines for distinguishing chronic granulocytic, atypical chronic myeloid, and chronic myelomonocytic leukaemia: Proposals by the French ‐ American ‐ British Cooperative Leukaemia Group

Abstract

We have reviewed our experience with four of the entities that are included under the generic term chronic myeloid leukaemia (CML), namely the classic Ph+ CGL, both BCR+ and BCR-, aCML and CMML. We have developed a statistical model that confirms that CGL, aCML and CMML can be distinguished from each other with reasonable success employing five quantitative parameters (WBC, percentage immature granulocytes, percentage monocytes, percentage basophils, percentage erythroid precursors in bone marrow) and one qualitative parameter (granulocytic dysplasia). It is hoped that these detailed recommendations will enable investigators to improve their diagnostic accuracy. This should permit more uniform comparisons of molecular biologic and clinical studies.

Clinicopathologic analysis of acute myeloid leukemia arising from chronic myelomonocytic leukemia

“…All of the acute myeloid leukemia ex chronic myelomonocytic leukemia cases with NPM1 and/or FLT3 mutation and available cytogenetic results had a normal karyotype. The 5 acute myeloid leukemia ex chronic myelomonocytic leukemia cases with NPM1 mutation had progressed to acute myeloid leukemia from [20] 46,XX,t(11;11)(p15;q23.1) [20] No 44,XY,del(2)(q13),-4,der(5)t(2;5)(q13;q13),-7,12, þ mar [3]/ 46,XY,t(7;21)(p13;q22),del(13)(q12q22) [2]/46,XY [7] 45,XY,t(7;21)(p12;q22),del (13) Transformed chronic myelomonocytic leukemia EL Courville et al chronic myelomonocytic leukemia in 0.5, 3, 3, 6, and 29 months; the acute myeloid leukemia case with unknown NPM1 mutation status but arising from NPM1-mutated chronic myelomonocytic leukemia had progressed to acute myeloid leukemia in 0.5 months.…”

“…In the initial French-American-British (FAB) classification, 1 chronic myelomonocytic leukemia was considered to be a subtype of myelodysplastic syndrome, but in 1994, the FAB group divided it into two types, 'proliferative' (chronic myelomonocytic leukemia-myeloproliferative type) and 'dysplastic' (chronic myelomonocytic leukemiamyelodysplastic type), based on a peripheral blood white blood cell count cutoff of 13 000/ml. 2 In 2001, the World Health Organization (WHO) subsequently classified chronic myelomonocytic leukemia within the group of myelodysplastic syndrome/ myeloproliferative disease neoplasms, but no longer distinguished proliferative and dysplastic subtypes. 3 Instead, the WHO recognized two subcategories (chronic myelomonocytic leukemia-1 and chronic myelomonocytic leukemia-2) based on the number of peripheral blood and bone marrow blasts, which appear to be the most important factors in predicting prognosis of chronic myelomonocytic leukemia patients.…”

Juvenile myelomonocytic leukemia and chronic myelomonocytic leukemia

“…During the 1990s, there were ongoing discussions at several different meetings and in some publications as to whether there should be a distinction between a proliferative type or version of CMML as opposed to a dysplastic type or version of CMML. 4,5 These discussions, or the criteria to delineate between the two types, were based largely on the total white blood cell count. In 2001, the World Health Organization (WHO) reclassified most of the hematologic malignancies.…”

Chronic neutrophilic leukemia (CNL): a clinical, pathologic and cytogenetic study

“…These features distinguish CNL from chronic myelogenous leukemia (CML), atypical chronic myeloid leukemia, and chronic myelomonocytic leukemia, as defined by the FrenchAmerican-British Cooperative Leukemia Group (FAB). 2 CNL should also be differentiated from the recently described neutrophilic-CML (CML-N), in which the Philadelphia chromosome is present but is associated with a novel BCR/ABL mol- ecular rearrangement (c3/a2 junction) that encodes for a 230 kDa fusion protein rather than the usual 210 kDa fusion protein associated with classic CML.…”