The frequency of clonal hematopoiesis in humans vastly increases with aging. Older adults may develop one or several clones and this condition is called clonal hematopoiesis of indeterminate potential (CHIP). Recent genetic analyses have identified the genes inducing CHIP. These mutant genes are detected frequently in elderly people and this condition is a precursor of hematopoietic neoplasms. The prevalence of hematopoietic neoplasms in patients with CHIP is tenfold that in those without CHIP. Consequently, the mechanism of aging and leukemogenesis of hematopoietic stem cells is being understood. Furthermore, the efficacy of senolysis, selectively removing scenescent cells from tissues, has been demonstrated in mice. The clinical application of senolysis is anticipated shortly.

Tyrosine kinase inhibitors (TKIs) have significantly improved the clinical outcomes of patients with chronic myeloid leukemia (CML). However, patients with CML need to receive TKI therapy for several years. Hence, the safety of long-term TKI treatment warrants utmost attention. Among various adverse events caused by TKI therapy, cardiovascular events (CVEs), such as acute myocardial infarction, cerebral infarction, and pulmonary hypertension, are the most serious with high mortality. TKIs inhibit various off-target molecules involved in the occurrence of CVEs such as c-Kit, platelet-derived growth factor receptor (PDGFR), vascular endothelial growth factor receptor (VEGFR), and Tie-2/Tec. At present, nilotinib, dasatinib, and ponatinib, but not bosutinib, have been demonstrated to increase the risk of CVEs in patients with CML compared with imatinib. Conversely, patients with CML have also been shown to have high CVE risks regardless of the TKI treatment compared with non-cancer population. Hence, further analyses are required to deduce the influence of TKI treatment on CVEs. Whatever the cause may be, to prevent CVEs in patients with CML, we need to appropriately screen and monitor CVE risks such as hypertension, serum glucose, lipid levels, ankle-brachial index (ABI), Electrocardiography (ECG), and echocardiography before and during TKI treatment.

The gastrointestinal tract is a common site for the occurrence of non-Hodgkin’s lymphoma (NHL). NHL with gastrointestinal lesions may lead to clinically relevant intestinal complications such as obstruction, perforation, and exsanguination during the course of the disease. Consequently, patients with NHL are often examined by means of upper and lower gastrointestinal endoscopy at the initial visit. There are no clear guidelines regarding which patients should undergo capsule endoscopy (CE) and balloon enteroscopy for detecting small intestinal lesions. We retrospectively examined the feasibility of detecting small intestinal lesions in NHL using upper and lower gastrointestinal endoscopy. Between January 2007 and October 2015, 198 patients with primary NHL were admitted to our hospital. We collected data from 51 patients with NHL with gastrointestinal lesions diagnosed through upper and lower gastrointestinal endoscopy, CE, or double balloon enteroscopy (DBE). We chosed these cases that gastrointestinal lesions was doubted by an examination for image. Nineteen of these patients presented with lymphoma at the duodenal bulb/descending part when examined by upper gastrointestinal endoscopy and at the distal ileum when examined by lower gastrointestinal endoscopy. Ectopic jejunoileal lymphoma was simultaneously detected in 13 of the 19 patients (68.4%) through the use of CE or DBE. Conversely, of the 32 patients who did not exhibit lesions at the duodenal bulb/descending part or at the distal ileum, 6 patients (18.8%) presented with small intestinal lesions, indicating a smaller percentage compared to the patients with ectopic jejunoileal lymphoma. Based on these findings, a proactive search for small intestinal lesions using CE or DBE is recommended in patients with NHL presenting with lymphoma at the duodenal bulb/descending part or at the distal ileum, as examined using both upper and lower gastrointestinal endoscopy during the initial visit.

Primary central nervous system lymphoma (PCNSL) is more difficult to treat than other lymphomas. Recently, it has been suggested that high-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is effective for treating PCNSL. In the present study, we retrospectively analyzed 12 patients with PCNSL at our hospital. Five young patients with good performance status (PS) received upfront ASCT. The conditioning regimen prior to ASCT with busulfan ＋ cyclophosphamide ＋ etoposide showed good prognosis (complete remission rate of 100%). In addition, the PS improved in patients treated with high-dose chemotherapy followed by ASCT, while it worsened in those treated without ASCT. Further investigations are needed to clarify inclusion/exclusion criteria and optimize conditioning regimens for ASCT.

A 68-year-old female with smoldering multiple myeloma (IgG-κ type) was admitted to the hospital owing to general fatigue, fever, and pain in the right leg. On the day following admission, she developed shock, and a blood culture revealed Streptococcus pneumoniae. She was diagnosed with septic shock and invasive pneumococcal disease (IPD). She received antibiotics and intravenous immunoglobulin and improved after several days. She had a history of recurrent IPD and had received the pneumococcal polysaccharide vaccine 23 (PPSV23) 2 years earlier. Therefore, we inquired with the National Institute of Infectious Diseases if the pneumococcal serotype isolated from her present IPD contained PPSV23. The results showed that her serotype was 19F, a serotype present in PPSV23. We administered pneumococcal conjugate vaccine 13 (PCV13) ; however, she was unable to mount high enough opsonophagocytic assay titers against some serotypes, including 19F. We think she was unable to mount effective humoral immune responses to PPSV23 or PCV13 owing to her underlying disease, smoldering myeloma. It should be considered how IPD can be effectively prevented in patients with multiple myeloma.

A 35-year-old man who previously underwent splenectomy for hereditary spherocytosis at age 29 visited our hospital complaining of fatigue that had started 7 days ago and right upper abdominal pain. Laboratory data showed increased white blood cell and eosinophil count accompanied by severe transaminitis and clotting abnormalities. Computed tomography scan showed multiple embolisms in the portal vein, superior mesenteric vein, right pulmonary artery, and inferior vena cava. Severe liver damage presumably caused by portal vein thrombosis was also observed. Anticoagulant therapies consisting of continuous arterial infusion of urokinase from the superior mesenteric artery and an intravenous infusion of recombinant human thrombomodulin and heparin dissolved the systemic thrombosis. Concurrently administered prednisone decreased the eosinophil count. With regard to eosinophilia, we were unable to find any connective tissue diseases, antibodies to parasites, or genetic anomalies including PDGFRA, PDGFRB, and FGFR1. Hence we diagnosed the patient with idiopathic hypereosinophilic syndrome (HES). Although thromboembolisms in patients with HES have been reported, the literature on portal vein thrombosis associated with HES is scarce. In the present case, the previous splenectomy may have contributed to the portal vein thrombosis.

A 69-year-old man visited a doctor because of systemic lymphadenopathy. Peripheral blood examination revealed leukocytosis, anemia, and decreased platelet count (WBC, 103,060/µl; lymph, 92.2%; Hb, 8.9 g/dl; and Plt, 4.1×10⁴/µl). Bone marrow biopsy revealed that approximately 70% of nucleated cells were small, mature lymphoid cells with positive immunostaining for CD5, CD20, and CD23. He was diagnosed with chronic lymphocytic leukemia (CLL). The IgH/CCND1 translocation and ATM locus loss in 20% and 95% peripheral cells, respectively, were detected by fluorescence in situ hybridization. Immunostaining revealed that cyclin D1 was positive in approximately 30% bone marrow cells. As the positive rate of CCND1 fusion signal was low, the diagnosis of mantle cell lymphoma was excluded. In contrast, signals of ATM locus deletion were detected in most tumor cells. Therefore, we assessed that IgH/CCND1 translocations occurred during the natural clinical course of CLL with ATM locus deletion from the onset of disease. The secondary IgH/CCND1 translocation in CLL is rare, and all reported cases with such translocations received treatments with alkylating agents. This is the first report regarding secondary IgH/CCND1 translocation during the natural clinical course of CLL and may provide insights into CLL pathogenesis.

The poor prognosis of extramedullary recurrence of acute leukemia following allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a therapeutic challenge, and thus far no effective treatment method has been established. Here, we report two patients who presented with relapsed leukemia as extramedullary tumor in the ovary following allo-HSCT. Case 1: A 23-year-old female underwent unrelated allogeneic bone marrow transplantation during the second remission of acute myeloid leukemia. After 706 days post-transplant, bilateral ovarian tumors were detected during the pelvic ultrasound, and extramedullary recurrence in the bilateral ovaries was subsequently established on right salpingo-oophorectomy and biopsy of the left ovary. Following completed systemic chemotherapy and total body irradiation, the patient underwent unrelated cord blood transplantation (CBT) and remission was maintained without recurrence for 7 years after second transplantation. Case 2: A 49-year-old female underwent unrelated CBT during the second remission of acute lymphocytic leukemia. At 372 days post-transplant, a pelvic tumor was detected by FDG-PET/CT, and extramedullary recurrence in the right ovary was diagnosed on examination of the resected pelvic mass. Chemotherapy and radiation were performed, but the tumor recurred on day 1,027 and the patient died on day 1,603. Extramedullary recurrence of adult acute leukemia as a mass in the ovary following allo-HSCT has been rarely reported. Therefore, further accumulation of related case reports is desired.

Allogeneic hematopoietic stem cell transplantation is recommended as a curative treatment option for fulminant aplastic anemia with no neutrophil despite the administration of granulocyte-colony stimulating factor. In the absence of an HLA-matched donor, unrelated cord blood transplantation (UCBT) is a treatment option that can be performed quickly. However, the optimal conditioning regimen of UCBT is yet to be established. We report two cases of fulminant aplastic anemia in adult patients who received UCBT. The first patient was a 52-year-old woman and the second was a 26-year-old man, both of whom received a conditioning regimen of total body irradiation (TBI; 2-4 Gy), fludarabine (Flu; 120 mg/kg), and cyclophosphamide (CY; 100 mg/kg) before UCBT. Short-term methotrexate and tacrolimus were used for prophylaxis of acute graft-versus-host disease (GVHD). Engraftments were achieved on days 26 and 19, and they exhibited complete donor chimerism by days 28 and 34. There was no evidence of acute GVHD, and therefore, the immunosuppressant drugs were discontinued. Reduced-intensity UCBT using a low-dose TBI/Flu/CY conditioning regimen could be an effective treatment option for fulminant aplastic anemia in the absence of a suitable donor.

A 59-year-old man who complained of abdominal pain was referred to our hospital. Computed tomography (CT) revealed mesenteric lymph node swelling and intestinal perforation. Histopathological study of the resected ileum and lymph node demonstrated diffuse proliferation of medium-sized atypical lymphocytes. Immunohistochemistry results were positive for cluster of differentiation (CD) 3, CD8, and CD56 cells, negative for CD5 and CD4 cells, and negative for Epstein-Barr virus-encoded RNA-fluorescent in situ hybridization (EBER-FISH). It also revealed the expression of γδ T-cell receptors. On the basis of these findings, enteropathy-associated T-cell lymphoma (EATL) was diagnosed. Although the patient received two courses of cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone (CHOP) and dexamethasone, etoposide, ifosfamide, and carboplatin (DeVIC) therapy, facial nerve and lower limb paralysis manifested. Magnetic resonance imaging (MRI) and lumbar puncture revealed central nervous system invasion of the EATL. Despite intrathecal chemotherapy and high-dose cytarabine therapy, the patient’s neurological symptoms deteriorated. Fluorodeoxyglucose positron emission tomography (FDG-PET) /CT scan showed the accumulation of FDG along both median and sciatic nerves, and he was diagnosed with neurolymphomatosis (NL). He died on day 120 after admission. Autopsy specimens exhibited infiltration of lymphoma cells in the median and sciatic nerves. Although only one case of suspected NL in a patient with type 2 EATL has been previously reported, we clinically diagnosed NL using FDG-PET/CT and confirmed the diagnosis by autopsy. This case is valuable in terms of the pathological diagnosis of NL.

A 9-year-old girl was referred to our hospital because of facial palsy. Both physical and blood examination revealed hepatosplenomegaly and leukocytosis, respectively. A bone marrow examination demonstrated marked hypercellularity involving myeloblasts and lymphoblasts. Based on these results, we suspected mixed phenotype acute leukemia. However, her leukemic blasts expressed B-cell antigens, and a chromosomal analysis of her bone marrow cells revealed the following karyotype: 46, XX, t (9;22) (q34;q11.2). All her neutrophils were positive for the breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 fusion protein. Based on these findings, she was diagnosed with a lymphoblastic crisis of chronic myelogenous leukemia (CML). Combined chemotherapy, involving imatinib, resulted in complete molecular remission. She received cord blood transplant (CBT) during the first complete remission; she is alive and has not suffered a relapse since two years after the CBT. The sudden onset of a blastic crisis in pediatric CML is rare, and it may be difficult to distinguish such cases from de novo Ph-positive leukemia. For diagnostic purposes, it is essential to consider a patient’s clinical course and blood test results.

Recent progress in sequencing studies has suggested that somatic mutations can be used in clinical sequencing for predicting prognosis and selecting treatment options in myelodysplastic syndrome (MDS). A 48-year-old man was diagnosed with refractory cytopenia with multilineage dysplasia that is classified as a subtype of high-risk MDS based on both revised International Prognostic Scoring System and refined WHO classification based Prognostic Scoring System. He received a bone marrow transplant from an HLA-matched sibling donor at X＋87 months because of disease progression. Targeted sequencing of 69 genes in bone marrow cells at X＋82 months revealed mutations in BCOR and U2AF1 genes. Variant allele frequencies of these mutations were almost unchanged in the bone marrow examined from X＋9 months to X＋80 months, but they subsequently decreased. Neither of these mutations was detected in the bone marrow at X＋88 months, a month after transplantation. The mutations often found in secondary leukemia or high-risk MDS were not detected in our patient. These serial genetic conditions may correspond to the relatively stable disease course over a long time.