Ph’-Positive (Ph’+) Chronic Myeloid Leukemia (CML) Presenting as Ph’+ T-Lymphoblastic Lymphoma (LL) Resistant to High-Dose Chemotherapy and Gleevec.
Authors: Falchi Lorenzo , Desantis Giorgia , Liberati Fabrizio , Pace Roberta , Morandi Maria G. , Scaravaglio Patrizia , Saglio Giuseppe , Liberati Anna M. 
Published: April 2020

BACKGROUND

Extramedullary blast crisis (BC) of Ph’+ CML is infrequent and commonly affects bone, lymphoid tissue, skin and soft tissues and central or peripheral nervous system. Most of nodal lymphoid tumors occuring in the setting of CML derive from T-cell precursors and represent the evolution of CML to a lymphoid nodal BC.

CASE HISTORY

In February 2004, a 52 year-old patient underwent diagnostic wide biopsy of a nasopharingeal mass that caused severe acute respiratory symptoms. At the histological examination, the nasopharyngeal mucosa exhibited a diffuse pattern of infiltration by neoplastic cells with a characteristic single-file arrangement. The cells showed typical convoluted nuclei with one or two nucleoli and abundant cytoplasm (L2, lymphoblasts). The malignant cell population expressed a preT-cell immunophenotype: cytoplasmic CD3(+), CD43 (+), TdT (+/−), CD34(+), CD4(−), CD8(−). Thus, the diagnosis of T-cell LL was formulated. Whole-body CT scan revealed nasopharingeal mass, retropharyngeal, laterocervical, axillary, inguinal enlarged nodes and splenomegaly. Laboratory tests indicated leukocytosis (58,000/μl) with a differential WBC count typical of CML in chronic phase (myeloblasts &lt;1%). This diagnosis was confirmed by a low alkaline phosphatase value (score: 1), histological features of bone marrow (BM) biopsy, classical cytogenetics (presence of the Ph’ in 100% of 25 metaphases analysed and absence of other cytogenetic abnormalities) and FISH evaluation (D-FISH bcr-abl in interphase and metaphase, Oncor probe). The nested RT-PCR (JQ Guo et al., Leukemia;2002,15:2447) disclosed the presence of the hybrid protein p210 (b2,a2), but not that of p190. A laterocervical node was excised to perform cytogenetic and molecular analyses in order to determine whether the T-cell LL was an unrelated disease or the expression of an extramedullary BC. The histology confirmed the presence of a uniform population of T-lymphoblasts in which classical cytogenetic analysis disclosed the following kariotype: 49,XY,t(9;22)(q34;q11),+9,+19,+der(22)t(9;22)(q34;q11) and 50–52,XY t(9;22)(q34;q11),+6+9,+9q+,+19,+20,+22q−. The FISH analysis showed the presence of bcr-abl gene in all cells analyzed and the presence of multiple copies of this gene as well as of double Ph’ chromosome. Nested RT-PCR showed the presence of both p210 and p190 transcripts. These findings indicated that the T-cell LL was an extramedullary BC of a CML simultaneously diagnosed in chronic phase in BM and peripheral blood. The patient was initially treated with vincristine, daunomicine, asparaginase and prednisone combined with Gleevec (800mg/die). Consolidation therapy, consisting of high-dose Ara-C (4g/m2 for 4 days) and mithoxantrone (10mg/m2 for 2 days), followed by a mieloablative course with mithoxantrone (60 mg/m2) and melphalan (180 mg/m2) and autologous stem cell support (ASCT) was administered after an initial clinical response. Gleevec was given during the entire treatment period. A fugacious complete clinical-hematological and a partial cytogenetic (FISH: 12% of cells bcr-abl+) and molecular (number of bcr-abl/104 ABL copies= 184, real-time quantitative RT-PCR: J Gabert et al., Leukemia;2003:1) remission was documented after ASCT. The patient refused further consolidation treatment with Gleevec and died, due to progressive disease, in December 2004.