Bilineal Extramedullary Blast Crisis as an Initial Presentation of Chronic Myeloid Leukemia: A Case Report and Literature Review

Abstract

Patient: Male, 49Final Diagnosis: T-lymphoid/myeloid bilineal blastic transformation of CMLSymptoms: Rapidly enlarging mass in left neckMedication: —Clinical Procedure: Biopsy of the left submandibular lymph nodesSpecialty: HematologyObjective:Rare co-existance of disease or pathologyBackground: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.

Incidental Neoplastic Tumours on Histo Pathology of Medico Legal Post Mortem Cases: A Ten Year Study

“…The patient was already a known case of CML and had progressed into blast phase. CML has been reported in extra-medullary organs in only 10% of cases by Inverardi et al and between 4 to 16% by Gao et al [9,10] A case of metastatic deposits of sarcoma in lung was seen (0.12%). This was again an incidental finding on autopsy.…”

Multiparametric Flow Cytometry in Mixed Phenotype Acute Leukemia

“…If the p210 transcript is present, CML in a mixed blast crisis should be considered in the differential diagnosis, especially if there are two distinct lymphoid and myeloid populations [5]. There are six such cases reported so far [17][18][19]. This is the seventh case of B/myeloid blast crisis reported till date.…”

Redistribution, homing and organ-invasion of neoplastic stem cells in myeloid neoplasms

“…Sometimes, organ invasion presents with a metastasis-like or even sarcoma-like, destructive growth of neoplastic cells in local tissue sites. Examples are myeloid sarcoma, localized blast phase of CML, and as mentioned above, mast cell sarcoma [26][27][28][29][30][31]. So far, little is known about mechanisms underlying re-distribution and extramedullary dissemination of pre-L-NSC and leukemic NSC (LSC) in myeloid neoplasms.…”