Chronic eosinophilic leukemia with t(6;11)(q27;q23) translocation

We report a rare case of chronic eosinophilic leukemia (CEL) with a chromos omal abnormality of t(6;11)(q27;q23). The patient was diagnosed as having t hyroid cancer with metastases to the lung and cervical lymph nodes in 1993. Percutaneous ethanol injection therapy (PEIT), total thyroidectomy, and ra diotherapy were performed. The patient was also diagnosed as having prostat ic cancer with bone metastasis in July 1999, and hormonal therapy was perfo rmed. At the time of the diagnosis of prostatic cancer, leukocytosis with e osinophilia was also revealed. Thereafter, cytogenetical analysis and rever se transcriptase polymerase chain reaction (RT PCR) analysis of bone marrow showed t(6;11)(q27;q23) translocation and MLL/AF6 fusion products, respect ively. No transcripts of the BCR/ABL chimeric gene were found by RT-PCR in bone marrow. Analysis of serum cytokines revealed a slight elevation of GM- CSF but no elevation of IL-3 or IL-5. Tissue damage due to infiltration of eosinophils was not observed throughout the clinical course. On the basis o f the cytogenetic and molecular abnormality, the patient was diagnosed as h aving CEL, rather than reactive eosinophilia due to thyroid or prostatic ca ncer or other reactive inflammation. This is the first case report of CEL w ith t(6;11)(q27;q23) translocation.