[Acute lymphoblastic leukemia with "masked" Philadelphia chromosome].

A 76-year-old woman with leukocytosis and thrombocytopenia was admitted to our hospital. A bone marrow examination showed a composition of 82.0% blasts, i.e., positive for TdT, CD10, CD19, CD34, and HLA-DR and negative for cyCD3, CD13, CD33, MPO, and cyµ. The reverse transcription-polymerase chain reaction analysis revealed a minor BCR-ABL1 fusion gene, leading to a diagnosis of acute lymphocytic leukemia (ALL) with a BCR-ABL1 fusion gene. G-band assay was negative for Philadelphia (Ph) chromosome and also revealed add (21) (q22. 1) and del (20) (q11. 2q13.3). Fluorescence in situ hybridization (FISH) assaying revealed a positive BCR-ABL1 fusion signal. Thus, this patient was diagnosed as Ph chromosome-negative and BCR-ABL1-positive fusion gene ALL, which suggested the presence of ALL with the "masked" Ph chromosome found in approximately 1% of chronic myeloid leukemia. Therefore, the FISH analysis may complement cytogenetic analysis when cytogenetic and molecular genetic findings are contradictory in ALL.

[De novo blast phase of chronic myeloid leukemia with 3q26 abnormality diagnosed by cytogenetic analysis of extramedullary lesion].

A 62-year-old woman was presented at our hospital with visual disturbance. An ocular examination revealed bilateral Roth spots. Laboratory data revealed leukocytosis (236,200 µl) with an excess blast (11%). Physical examination and computed tomography (CT) showed systemic lymphadenopathy. A bone marrow examination revealed a composition of 9.2% blast. Chromosomal analysis on bone marrow cells revealed 46,XX,t (3;12)(q26.2;p13),t (9;22)(q34.1;q11.2) in 80% of metaphases (16/20). Inguinal lymph node biopsy revealed diffuse proliferation of myeloperoxidase (MPO)-positive abnormal cells. Fluorescence in situ hybridization analysis was used to detect the BCR-ABL1 fusion gene and split the signals of MECOM and ETV6. She was diagnosed with de-novo chronic myeloid leukemia (CML) extramedullary blast crisis. She received tyrosine kinase inhibitor (TKI) combination chemotherapy and allogeneic hematopoietic stem cell transplantation and achieved a major molecular response. In this study, we reported a case of CML in blast-phase initially presenting as extramedullary, in which cytogenetic and molecular analyses were useful in the staging method.

Efficacy and Safety of Anti-Programed Death-1 Blockade in Previously Treated Large-Cell Neuroendocrine Carcinoma.

BACKGROUND: Large-cell neuroendocrine carcinoma (LCNEC) of the lung is a rare tumor with an aggressive clinical course. However, there is limited knowledge of its treatment strategy. This retrospective study aimed to assess the efficacy and safety of anti-programed death-1 (PD-1) blockade monotherapy in previously treated advanced LCNEC. METHODS: Eleven patients with previously treated advanced LCNEC who received immune checkpoint inhibitor monotherapy between January 2015 and November 2020 were retrospectively analyzed for efficacy and safety. RESULTS: Of a total of 11 patients (median [range] age, 66 [37-79] years; 8 men [73%] and 3 women [27%]), 8 patients had performance status (PS) 0-1 [73%] and 3 patients had PS 2 [27%]; 9 patients received 1 prior chemotherapy [82%] and 2 patients received 2 prior chemotherapies [18%]. The median follow-up duration was 4.6 months. Although PD-1 blockade was administered at median cycles of 3 (range, 1-12), overall response rate, median progression-free survival, and median overall survival were 9.1%, 2.7 months, and 4.6 months, respectively. Any adverse events were observed in 9 patients (82%), including 1 patient with grade 3 pneumonitis as a serious adverse event. CONCLUSION: Anti-PD-1 blockade monotherapy as a subsequent line for previously treated advanced LCNEC exhibited usefulness and tolerability and was identified as a valid treatment option.

Acute Myocardial Infarction in an Adolescent Receiving Anagrelide for Essential Thrombocythemia with Underlying Persistent Coronary Endothelial Dysfunction.

Essential thrombocythemia (ET) is a Philadelphia chromosome-negative myeloproliferative disorder that is characterized by the overproduction of platelets and a marked increase in the numbers of mature megakaryocytes present in the bone marrow. Thrombohemorrhagic disorders are major morbidities of ET, especially those with mutations in the gene encoding Janus kinase 2 (JAK2). In this study, we report the case of an 18-year-old patient with ET carrying JAK2 mutation who developed acute ST-elevation myocardial infarction (STEMI) 5 months after a commencement of anagrelide. Coronary endothelial dysfunction confirmed by positive acetylcholine provocation test lasted a year after the occurrence of STEMI. Furthermore, intracoronary imaging using optical coherence tomography demonstrated non-atheromatous intimal fibrosis possibly due to chronic endothelial damage. The coronary pathologies reflected chronic change potentially associated with properties of ET and JAK2 mutation in addition to hyperviscosity. These observations suggest that the side effect of anagrelide in our patient was considered causative, while underlying chronic endothelial dysfunction and adverse endothelial remodeling may be predisposing factors to his fatal cardiovascular events.

An Autopsy Case of Late-onset Fulminant Myocarditis Induced by Nivolumab in Gastric Cancer.

Nivolumab is an immune-checkpoint inhibitor (ICI) that can induce unique treatment-related toxicities, such as immune-related adverse events (irAEs). Myocarditis is a serious irAE with an incidence between 0.06% and 1.14%. Although the peak onset of irAE is generally within three months from the start of treatment, we experienced an autopsy case of late-onset fulminant myocarditis caused by nivolumab in Epstein Barr virus-associated gastric cancer. Pathological complete remission of the primary lesion was confirmed by the autopsy. We should consider possible complications of cardiac irAEs, especially fulminant myocarditis, even beyond three months after starting ICI therapy.

Molecular Genetic Analysis With Flow Cytometry Sorting Identifies Angioimmunoblastic T-Cell Lymphoma and Concomitant De Novo Myelodysplastic Syndrome Arising From the Same Hematopoietic Progenitor.

A 75-year-old man with no prior history of cytotoxic therapy presented with increasing fatigue and shortness of breath. He was found to have a new onset of pancytopenia, and chest X-ray showed severe pneumonia. Additional radiology exam revealed pan-lobar pneumonia, pleural effusion, generalized lymphadenopathy and mild splenomegaly. Bone marrow and mediastinal lymph node biopsy from the bilateral level 4 lymph nodes were performed to evaluate the cause of pancytopenia and generalized lymphadenopathy, respectively. Histologic sections of lymph nodes were consistent with angioimmunoblastic T-cell lymphoma (AITL), and bone marrow biopsy showed low level involvement by AITL. Background trilineage hematopoiesis showed features suggestive of myelodysplastic syndrome (MDS) with karyotyping showing deletion 20q; however, interpretation of dysplasia and exclusion of reactive process was difficult due to the presence of severe infection, administration of multiple medications and multiorgan failure. Therefore, to further evaluate the possibility of concomitant myeloid neoplasm, we performed flow cytometry sorting of bone marrow aspirate to isolate the myeloid cell population from the abnormal T-cell population, and comprehensive genomic profiling was performed in each population separately. Flow-sorted myeloid population showed three somatic mutations involving DNMT3A and BCORL1, supporting the diagnosis of MDS in conjunction with the presence of deletion 20q. Flow sorted abnormal T-cell population showed six somatic mutations consistent with AITL, involving Ras homolog gene family member A (RHOA), TET2, DNMT3A, NOTCH2 and XPO1. These two sorted populations shared the DNMT3A p.N612Rfs*26 mutation, and the variants unique to one sorted population were confirmed to be completely absent in another sorted population by manual review of the sample. These findings suggested that the two neoplasms were clonally related and were sharing a common hematopoietic progenitor precursor, but underwent clonal divergence over time, leading to the development of two distinct neoplastic processes of T and myeloid lineages. This illustrates a rare case of concurrent diagnosis of AITL and de novo MDS and reliable genomic assessment was performed at the time of diagnosis to detect mutations in each neoplastic process without contamination. Further studies are needed to assess hypomethylating agents as potential therapy options for these patients.