164 Coexistence of Acute Promyelocytic Leukemia and Hairy Cell Leukemia: A Case Report

Acute promyelocytic leukemia and hairy cell leukemia are two distinct hematologic malignancies. Coexistence of these two pathologies has not been reported previously.

We report a case of a 69-year-old woman from Grenada who presented with pancytopenia. Laboratory findings, morphology, immunophenotyping, mutational analysis, and cytogenetic investigation supported the diagnosis of acute promyelocytic leukemia, including PML/RAR gene rearrangement and t(15;17)(q24;q21.2) in support of the diagnosis. In a fraction of the bone marrow content, however, the morphology and immunophenotyping indicated that the coexisting neoplasia is hairy cell leukemia. We did not find any treatment-related effect that could have contributed to the development of coexisting acute promyelocytic leukemia and hairy cell leukemia.

At present, management is focused on treating the acute promyelocytic leukemia and monitoring the hairy cell leukemia. The clonal relationship between these two neoplasias is under investigation by using cell linage specific interphase cytogenetic analysis.