A diagnostic dilemma: chronic myelomonocytic leukemia versus atypical chronic myeloid leukemia. A case report and review of the literature.

There exists a great deal of overlap between many myelodysplastic syndromes and myeloproliferative disorders. This is most evident in the spectrum of disorders classified under the term chronic myeloid leukemia. These include chronic granulocytic leukemia, atypical chronic myeloid leukemia and chronic myelomonocytic leukemia. Current classification often does not clearly separate these entities since they share many features, both clinically and hematologically. We report here a case that satisfies criteria for both chronic myelomonocytic leukemia and atypical chronic myeloid leukemia, appearing to fluctuate between the two. This lends further evidence for the heterogeneity of these disorders and the need for better definition. An improved classification scheme would allow for more accurate reporting and research into etiology and treatment. The complex cytogenetic abnormalities of the case are unique and to our knowledge have not been reported previously. Also, this case report underscores the importance of cytochemical stains when such disorders are under consideration.