[Extramedullary blastic crisis of chronic myelogenous leukemia--a case with various additional chromosomal appearance].

We describe a characteristic case of chromosomal abnormalities in a 47-year-old man with chronic myelogenous leukemia (CML). He had been diagnosed with the chronic phase of CML on May 1990, but he refused treatment. He was readmitted in October 1991 because of peripheral lymphadenopathy. Hematologic studies showed that he remained in the chronic phase of CML. There were no additional chromosomal findings in the bone marrow, but cervical lymph node biopsy revealed complete replacement with blastoid cells. The blasts were positive for CD13 and CD33. DNA analysis for the breakpoint cluster region gene showed rearrangement pattern, but immunoglobulin heavy chain joining region genes and T-cell antigen receptor gene rearrangement were not observed. The karyotype of lymph node cells showed various additional chromosomal abnormalities. Therefore, we concluded that the patient had an extramedullary blastic crisis in his peripheral lymph nodes. Abnormal clones were composed of one main clone and three subclones, with the latter occupying more than 10% of the volume each other. Considering the types of the additional chromosomal abnormalities, all four types of clones were thought to have evolved through independent pathways.