[A Case of Philadelphia Chromosome-Positive Acute Myeloid Leukemia Extramedullary Recurrence in a Patient Undergoing Thoracoscopy for Massive Pleural Effusion].

A man in his early 70s visited a previous hospital because of pancytopenia and was diagnosed with acute myeloid leukemia based on a bone marrowexamination. The karyotype was 46,XY, t(9;22)(q34;q11.2)[2/20], and real-time polymerase chain reaction(PCR)revealed minor bcr-abl chimeric mRNA. Finally, the patient was judged as having Philadelphia chromosome- positive acute myeloid leukemia, and remission induction chemotherapy with the JALSG AML 201 protocol was initiated in combination with dasatinib to achieve complete remission. After 3 courses of consolidation chemotherapy, the anticancer drugs were discontinued because of deterioration of his general condition and renal insufficiency. Six months after the initial treatment, he was referred to our department, and no evidence of recurrence was confirmed on bone marrow examination. However, 2 months later, right massive pleural effusion was detected, and he was admitted to the department of pneumology at our hospital. Thoracoscopic pleural biopsy was performed at the time of chest tube insertion, and he was diagnosed with acute myeloid leukemia extramedullary recurrence. Peripheral myeloblasts appeared and increased rapidly, accompanied by further exacerbation of renal function; thus, he received palliative care at the department of hematology and oncology.