Unusual T-lymphoblastic blast phase of chronic myelogenous leukemia

Bi-lineage B- and T-lymphoid Extramedullary Blast Crisis at an Initial Presentation of Chronic Myeloid Leukemia: A Case Report and Literature Review of Extramedullary Blast Crisis

Chronic myeloid leukemia (CML) with BCR-ABL1-positive cells is a myeloproliferative neoplasm (MPN) characterized by a chromosomal translocation t(9,22)(q34.1;q11.2), which results in the formation of a Philadelphia (Ph) chromosome containing the BCR-ABL1 fusion gene. Extramedullary blast crisis (EBC) associated with bcr/abl-positive CML is a rare initial presentation. Here, we present and discuss the case of a 51-year-old man who presented with a weight loss history, cervical swelling, and left-sided abdominal pain. He had a white blood cell count of 147,910/mm3. The blood smear study revealed myelemia in 23% and 8% of blast-like cells. The bone marrow aspiration and biopsy showed a richly cellularized sample; the megakaryocytes were present; the granular neutrophil line was at 89% with blasts at 1%. The cytogenetic analysis revealed a complex karyotype with the presence of a Philadelphia chromosome t (9, 22) (q34, q11) associated with additional cytogenetic abnormalities (ACA). Molecular analysis (PCR) detected a BCR::ABL1 (p210) rearrangement. At this point, a diagnosis of CML in the chronic phase was confirmed, but a cervical lymph node biopsy analysis revealed a bi-phenotypic B/T-lymphoblastic lymphoma (LBL) and expressed at fluorescent in situ hybridization (FISH) analysis BCR::ABL1 rearrangement. These findings were consistent with the diagnosis of a bi-phenotypic B/T extramedullary blast crisis associated with CML.

A Case Report of Chronic Myelogenous Leukemia Presenting as Blastic Crisis with a T-Cell Acute Lymphoblastic Leukemia Phenotype: Awareness of a Rare Entity

Chronic myelogenous leukemia at blast crisis with a T-cell phenotype (T-ALL CML-BC) at diagnosis, without any prior history of CML is extremely rare. After the introduction of tyrosine kinase inhibitors (TKIs), CML patients have a median survival comparable to general population and accelerated/blast crisis are rarely encountered. Most CML patients (80%) transform into acute myeloid leukemia and the rest into B-ALL. Anecdotal cases of Ph+ T-ALL, either de novo or in the context of CML-BC have been reported. Left shift in the blood, the presence of splenomegaly/extramedullary infiltration and the occurrence of BCR::ABL1 rearrangement in both the blastic population, as well as in the myeloid cell compartment are key points in differentiating de novo Ph+ T-ALL from T-ALL CML-BC. The latter is a rare entity, characterized by extramedullary disease, p210 transcript and clonal evolution. Lack of preceding CML does not rule out the diagnosis of T-ALL CML-BC. Prompt TKI treatment with ALL-directed therapy followed by allogeneic stem cell transplantation may offer long-term survival in this otherwise poor prognosis entity. In this paper, we describe a patient with T-ALL CML-BC at presentation, still alive 51 months after diagnosis and we offer a review of the literature on this rare subject. All clinical and laboratory features are provided in order to distinguish de novo Ph+ T-ALL from T-ALL CML-BC, underscoring the prognostic and therapeutic significance of such a differentiation.

An unusual case of T-cell acute lymphoblastic leukemia in a patient with BCR-ABL positive chronic myeloid leukemia and Gaucher disease

Background

Chronic myelogenous leukemia (CML) is a chronic myeloproliferative disease characterized by a massive overproduction of myeloid cells. It is associated with the Philadelphia chromosome [Ph1, t (9; 22) (q34; q11)] or BCR-ABL fusion gene. CML usually undergoes a triphasic clinical course ending in a blast crisis, an accelerated phase of blasts and promyelocyte production. Ten percent of CML patients reach the blast crisis phase, with 20–30% of leukemias belonging to B-cell lymphoid lineage. However, a transformation of CML into T-cell acute lymphoblastic leukemia (T-ALL) is rare.

Case presentation

We present a 56-year-old male patient, known case of hypertension and Ph1 CML of eight years with a family history of Gaucher disease who developed T-ALL. The patient presented with lymphadenopathy and severe anemia, needing packed RBC transfusion, neutropenia and thrombocytopenia at the admission. However, the monocytes and basophils percentage were high. The patient underwent a cervical lymph node core biopsy, and the immunohistochemistry stains showed an invasion of neoplastic cells positive for CD3, CD5, BCL2, CD34, TdT and focally positive for C-Kit and negative for CD20, CD56 and pan-CK. These histopathology features were consistent with T-cell acute lymphoblastic leukemia (T-ALL).

Conclusion

Blast crisis remain a challenge in CML management. It's of great importance to do a full proper workup including lymph nodes biopsies. The aim is to reverse blast crisis and restore the chronic phase.

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Even if CML normally transforms into B-ALL, it can also manifest as T-ALL.

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Careful history taking, meticulous physical examination, and investigations are necessary.

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Avoiding the blast crisis is very important in order to prevent its transformation.

A Rare Case of Chronic Myelogenous Leukemia Presenting as T-Cell Lymphoblastic Crisis

Chronic Myelogenous Leukemia in blast crisis can manifest as either myeloid (more common) or lymphoid blast crisis. Most lymphoblastic crises are of B-cell lineage. T-cell blast crisis is extremely rare, with only a few reported cases. We present a case of a middle-aged man who was diagnosed with CML on peripheral blood and bone marrow biopsy. Because of a generalized lymphadenopathy noted at the time of diagnosis, a lymph node biopsy was also performed, which revealed a T-cell lymphoblastic leukemia/lymphoma, BCR/ABL1 positive, with clonal evolution. This is a very rare manifestation of CML in blast crisis with no standard treatment and with poor outcomes despite chemotherapy or allogeneic stem cell transplant. Given its rarity, it would be difficult to develop standard chemotherapy protocols. We believe the treatment for this condition should be similar to any lymphoid blast crisis. The patient was treated with induction chemotherapy (hyper-CVAD regimen) plus dasatinib for 3 cycles followed by sibling-donor allogeneic stem cell transplant and is currently on maintenance dasatinib and has minimal residual disease at this time.