A novel BCR-ABL1 mutation in a patient with Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) represents the most common genetic subtype of adult ALL (20%-30%) and accounts for approximately 50% of all cases in the elderly. It has been considered the subgroup of ALL with the worst outcome. The introduction of tyrosine kinase inhibitors (TKIs) allows complete hematologic remission virtually in all patients, with improved disease-free survival and overall survival. Nevertheless, the emergence of resistant mutations in BCR-ABL1 may require different TKI strategies to overcome the patient's resistance and disease relapse. Here, we report a Ph+B-ALL case with persistent minimal residual disease (MRD) after treatment with dasatinib. The patient expressed the P190BCR-ABL1 isoform and a novel BCR-ABL1 mutation, p.Y440C. The latter is in the C-terminal lobe of the kinase domain, which likely induces deviations in the protein structure and activity and destabilizes its inactive conformation. The treatment was substituted by bosutinib, which binds to the active conformation of the protein, prior to allogeneic bone marrow transplant to overcome the lack of a complete response to dasatinib. These findings strengthen the importance of BCR-ABL1 mutational screening in Ph+ patients, particularly for those who do not achieve complete molecular remission.

Autologous stem cell transplantation for primary mediastinal B-cell lymphoma: long-term outcome and role of post-transplant radiotherapy. A report of the European Society for Blood and Marrow Transplantation.

The purpose of this retrospective registry study was to investigate the outcome of autoSCT for primary mediastinal B-cell lymphoma (PMBCL) in the rituximab era, including the effects of eventual post-transplant radiotherapy (RT) consolidation. Patients with PMBCL aged between 18 and 70 years who were treated with a first autoSCT between 2000 and 2012 and registered with the EBMT were eligible. Eighty-six patients with confirmed PMBCL and the full data set required for this analysis were evaluable. Sixteen patients underwent autoSCT in remission after first-line therapy (CR/PR1), 44 patients were transplanted with chemosensitive relapsed or primary refractory disease (CR/PR >1), and 24 patients were chemorefractory at the time of autoSCT. With a median follow-up of 5 years, 3-year estimates of relapse incidence, progression-free survival, and overall survival were 6%, 94%, and 100% for CR/PR1; 31%, 64%, and 85% for CR/PR >1; and 52%, 39%, and 41% for REF, respectively. Whilst there was no significant benefit of post-transplant RT in the CR/PR >1 group, RT could completely prevent disease recurrence post d100 in the refractory group. In conclusion, autoSCT with or without consolidating RT is associated with excellent outcome in chemoimmunotherapy-sensitive PMBCL, whereas its benefits seem to be limited in chemoimmunotherapy-refractory disease.

What is the role of JAK2(V617F) mutation in leukemic transformation of myeloproliferative neoplasms?

BACKGROUND AND OBJECTIVES: The role of the Janus kinase 2 V617F (JAK2(V617F)) mutation in the pathogenesis of the various BCR-ABL1-negative myeloproliferative neoplasms (MPNs) remains unclear. Its significance in leukemic transformation is a matter of even greater controversy. The aim of this study was to evaluate both the JAK2(V617F) mutational status of the rare cases in which blast crisis occurred in our institution and the response after intensive treatment. MATERIALS AND METHODS: Between 1999 and 2009, 778 patients received diagnoses of BCR-ABL1-negative MPNs in our center (395 polycythemia vera, 329 essential thrombocythemia, and 45 primary myelofibrosis cases, as well as 9 MPN cases not otherwise classifiable). Of these patients, 7 developed leukemic transformation. The genotyping of the JAK2(V617F) mutation was performed by the amplification-refractory mutation system. RESULTS: Six of the 7 patients were tested for JAK2(V617F) in the chronic phase of their disease, and 3 of these patients were positive for JAK2(V617F). These patients, 2 with polycythemia vera and 1 with essential thrombocythemia, also harbored JAK2(V617F) in the heterozygous state during blast crisis and even after intensive treatment in one of these patients. The other cases that evolved to blast crisis did not harbor the JAK2(V617F) mutation before and after transformation. All 7 patients died despite conventional or supportive treatment. CONCLUSIONS: The transformation of MPNs into acute leukemia is by itself a very rare phenomenon, and so is the persistence of the JAK2(V617F) mutation after blast crisis. In our series, all JAK2(V617F)-positive patients remained positive for this mutation after leukemic transformation, although in the heterozygous state, suggesting that JAK2(V617F) is not essential for transformation in these cases. The fact that all JAK2(V617F)-negative cases remained negative after blast crisis reinforces the theory that other molecular event(s) may play a role in the clonal heterogeneity of MPNs. Owing to the poor outcome of acute myeloid leukemia secondary to MPN, patients should be included in clinical trials of the novel JAK2 inhibitors.

B lymphoblastic lymphoma presenting as a tumor of the nasopharynx in an adult patient.

In adults, non-Hodgkin's lymphoma (NHL) is the second most common neoplasm found in the head and neck region after squamous cell carcinoma. Within this region, primary NHL of the nasopharynx is rare. We report the case of a 28-year-old male diagnosed with a B lymphoblastic lymphoma (CD20-; CD79a+; CD3-; CD10+; PAX5+, CyclinD1-; TdT+) of the nasopharynx extending to the deep and superficial structures of the right hemiface, to the skull base with an intracranial component and a small but detectable bone marrow involvement, who was started on chemotherapy with a complete response. To the best of our knowledge, this is the first case of a primary nasopharynx B-LBL in an adult patient with such aggressive regional spread to be reported in the literature.

Early Diagnosis of Invasive Aspergillosis in Neutropenic Patients. Comparison between Serum Galactomannan and Polymerase Chain Reaction.

BACKGROUND: Invasive aspergillosis (IA) is a major cause of morbidity and mortality in profoundly neutropenic patients, so early diagnosis is mandatory. AIM: Consecutive patients with hematological malignancies undergoing intensive chemotherapy were screened for IA with two different methods which were compared. METHODS: From October 2000 to August 2003 we tested 1311 serum samples from 172 consecutive patients with a polymerase chain reaction assay and between April 2005 and April 2008 we tested 806 serum samples from 169 consecutive patients with a Galactomannan (GM) test. Bronchoalveolar (BAL) samples were obtained whenever the patient's condition allowed and tested with either method. RESULTS: The serum PCR assay had a sensitivity of 75.0% and a specificity of 91.9% and the serum GM assay had a sensitivity of 87.5% and a specificity of 93.1%, (P > 0.05). The presence of two or more consecutive positive serum samples was predictive of IA for both assays. BAL GM/PCR was positive in some patients without serum positivity and in patients with 2 or more positive serum GM/PCR. CONCLUSIONS: No significant differences between the 2 serum tests were found. The GM assay has the advantage of being standardized among several laboratories and is incorporated in the criteria established by the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycosis Study Group (EORTC/MSG), however is much more expensive. BAL GM and PCR sampling aids in IA diagnosis but needs further validation studies to differentiate between colonization and true infection in cases where serum GM or PCR are negative.