title: Morphological and immunological pattern of blastic transformation in chronic myeloid leukemia in Saudi Arabia: Study of 90 transformations among 248 patients.
abstract: We examined the pattern of blastic transformation in 90 of 248 patients (36%) with chronic myeloid leukemia who were seen at the King Faisal Specialist Hospital and Research Centre between 1975 and 1988. The mean and median ages of all patients were 38.2 and 36.0 years, respectively. Four of the 90 transformants (4.4%) presented in blastic transformation, and 86 cases (95.5%) evolved from a well-defined chronic phase. Twenty-nine (32.2%) of the patients underwent lymphoid blastic transformation, while 28 (31.1%) were myeloid, seven (7.8%) were myelomonocytic, four (4.4%) were monocytic or erythroblastic, six (6.7%) were megakaryoblastic, ten (11.1%) were of mixed lineage, and two (2.2%) were unclassifiable. The lymphoid blast cells were uniformly common acute lymphocytic leukemia (i.e., Ia and CD10 positive), whereas the myeloid transformations were predominantly Ia negative. Mixed phenotype blasts were also predominantly Ia positive (i.e., 8 of 10), with varying positively for CD10 and myeloid/monocyctic markers. We conclude that blast crisis in chronic myeloid leukemia occurs in Saudi patients in a pattern similar to that seen in patients elsewhere, and that surface Ia antigen positivity in lymphoblast cells is a reliable marker for differentiating lymphoid from nonlymphoid crisis, in which the Ia antigen is not usually demonstrable.
authors.affiliation: Department of Pathology and Laboratory Medicine, and Department of Oncology, King Faisal Specialist Hospital, Riyadh, Saudi Arabia.
authors.forename: G T
authors.initials: GT
authors.lastname: Roberts
authors.forename: M A
authors.initials: MA
authors.lastname: Padmos
authors.forename: H
authors.initials: H
authors.lastname: Clink
authors.forename: D G
authors.initials: DG
authors.lastname: Spence
authors.forename: P
authors.initials: P
authors.lastname: Ernst
authors.forename: K V
authors.initials: KV
authors.lastname: Sheth