title: Bilineal Extramedullary Blast Crisis as an Initial Presentation of Chronic Myeloid Leukemia: A Case Report and Literature Review.
abstract: BACKGROUND Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the Philadelphia chromosome generated by the reciprocal translocation t(9: 22)(q34;q11). CML is usually diagnosed in the chronic phase. Blast crisis represents an advanced phase of CML. Extramedullary blast crisis as the initial presentation of CML with bone marrow remaining in chronic phase is an unusual event. Further, extramedullary blast crisis with T lymphoid/myeloid bilineal phenotype as an initial presentation for CML is extremely unusual. CASE REPORT Here, we report the case of a 49-year-old male with rapidly enlarged submandibular lymph nodes. Biopsy specimen from the nodes revealed a characteristic appearance with morphologically and immunohistochemically distinct myeloblasts and T lymphoblasts co-localized in 2 adjacent regions, accompanied by chronic phase of the disease in bone marrow. The presence of the BCR/ABL1 fusion gene within both cellular populations in this case confirmed the extramedullary disease represented a localized T lymphoid/myeloid bilineal blastic transformation of CML. After 3 courses of combined chemotherapy plus tyrosine kinase inhibitor treatment, the mass was completely regressed with a 3-log decrease in BCR/ABL1 transcript from baseline. Five months after the diagnosis, the patient showed diminished vision, hand tremors, and weakness of lower extremities. Flow cytometric immunophenotyping of cerebrospinal fluid revealed the presence of myeloid blasts. An isolated central nervous system relapse of leukemia was identified. Following high-dose systemic and intrathecal chemotherapy, the patient continued to do well. CONCLUSIONS The possibility of extramedullary blast crisis as an initial presentation in patients with CML should be considered. Further, an isolated central nervous system blast crisis should be considered if neurological symptoms evolve in patients who have shown a good response to therapy.
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Xiaoning
authors: X
authors: Gao
authors: Department of Pathology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Jie
authors: J
authors: Li
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Lili
authors: L
authors: Wang
authors: Institute of Basic Medicine, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Ji
authors: J
authors: Lin
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Hongshi
authors: H
authors: Jin
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Yihan
authors: Y
authors: Xu
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Nan
authors: N
authors: Wang
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Yu
authors: Y
authors: Zhao
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Daihong
authors: D
authors: Liu
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Li
authors: L
authors: Yu
authors: Department of Hematology, Chinese PLA General Hospital, Medical School of Chinese PLA, Beijing, China (mainland).
authors: Quanshun
authors: Q
authors: Wang
mesh_terms: D001752:Blast Crisis; D001854:Bone Marrow Cells / Q000473:pathology*; D005434:Flow Cytometry; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D013601:T-Lymphocytes / Q000473:pathology*; D014057:Tomography, X-Ray Computed