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Importance of molecular confirmation in the diagnosis of myeloproliferative disorders
William W. Backus Hospital, Norwich, CT, and University of Connecticut Health Center, Farmington, CT
The presence of the Philadelphia (Ph) chromosome is a hallmark for the diagnosis of chronic myeloid leukemia (CML). Here, we report a cytogenetically ascertained Ph-positive case with pathological features of a myeloproliferative disorder consistent with CML. No cytogenetic improvement was observed following 7 years of treatment, despite a hematological remission. Subsequent molecular studies revealed the absence of BCR/ABL fusion products. The purported “Ph chromosome” was found to be derived from a constitutional t(12;22) translocation instead of an acquired t(9;22;12). An acquired point mutation, V617F, was subsequently identified in the JAK2 gene of the patient. The diagnosis was therefore changed from CML to essential thrombocythemia, and treatment with anagrelide has been effective. This case illustrates the importance of molecular confirmation in the diagnosis of myeloproliferative disorders.
| Commun Oncol 2005;2:418–422 | full text |  127 kb |