Primary central nervous system lymphoma (PCNSL) is a rare, aggressive type of non-Hodgkin lymphoma with a poor prognosis and no defined optimal therapeutic strategies. We retrospectively analyzed the survival of six PCNSL patients who were treated with high-dose methotrexate (HDMTX) -based chemotherapy combined with rituximab. The median age at diagnosis was 71 (range, 54-75) years, and the ECOG performance status was ≥3 in four patients. The histopathological findings revealed that all patients had diffuse large B-cell lymphoma. Objective response was obtained in all patients (five, complete response; one, partial response). Three patients had severe non-hematological toxicities: one had pulmonary thromboembolism, one had sepsis, and one developed acute epididymitis. However, each patient recovered and their symptoms could be managed. The median follow-up was 28.8 (range, 13.4-65.5) months. Five patients were still alive and disease-free, and one patient relapsed 62.2 months after the diagnosis. Therefore, the addition of rituximab to HDMTX may improve outcomes. Further clinical investigation is necessary to establish standardized initial therapies for PCNSL, particularly in elderly patients.

A 68-year-old female with severe aplastic anemia (SAA) refractory to initial immunosuppressive therapy, including anti-thymocyte globulin (ATG) and cyclosporine, received a reduced-intensity cord blood transplant (CBT) in June 2015. Tacrolimus (TAC) and mycophenolate mofetil were administered for graft-versus-host disease (GVHD) prophylaxis, and she received prolonged TAC and prednisolone to treat chronic GVHD. The patient presented with progressive ataxia 14 months after CBT. A brain magnetic resonance image (MRI, FLAIR) detected a high-intensity lesion in the left cerebellar hemisphere, which suggested infarction. Her consciousness level gradually continued to deteriorate and another brain MRI (T2) revealed that the size of the cerebellar lesion had increased and had involved the pons. A cerebrospinal fluid (CSF) examination showed normal cell count and protein levels; however, polymerase chain reaction (PCR) analysis of CSF was positive for JC virus (JCV). Therefore, she was eventually diagnosed with progressive multifocal leukoencephalopathy (PML) and treated with mefloquine. The symptoms were reduced after 3 months, and JCV in CSF disappeared without new lesions after 6 months. This is an unusual case of PML initially involving the cerebellum, and we report here PML after an immunosuppressive therapy and CBT in the patient with SAA.

Acute megakaryoblastic leukemia in children without Down syndrome (non-DS AMKL) is considered to be a poor prognostic subtype in acute myeloid leukemia. Recently, some chimeric fusion genes were found in pediatric non-DS AMKL; therefore, we attempted to detect chimeric fusion genes RBM15-MKL1, CBFA2T3-GLIS2, and NUP98-KDM5A from 10 pediatric non-DS AMKL diagnostic samples using polymerase chain reaction and Sanger sequencing methods. Two samples were positive for RBM15-MKL1, four had CBFA2T3-GLIS2, and only one case had NUP98-KDM5A. Both RBM15-MKL1-positive patients showed long-term remission after chemotherapy. The eight RBM15-MKL1-negative patients received hematopoietic stem cell transplantation (HSCT). In four CBFA2T3-GLIS2-positive patients, three had HSCT without complete remission and two of themdied. Additional treatment stratification depending on chimeric fusion genes and development of new therapeutic drugs are required for non-DS AMKL.

A 64-year-old man presented to the emergency department with sudden-onset upper abdominal pain and pain in the left chest area. His platelet count was 121.7×10⁴/µl. Computed tomography (CT) showed bilateral adrenal swelling and inflammation of the adjacent tissue. Diffusion-weighted magnetic resonance imaging (MRI) showed hyperintensity in the bilateral adrenal glands. The patient was diagnosed with bilateral adrenal infarction. A bone marrow biopsy yielded a diagnosis of essential thrombocythemia, and a positive JAK2 V617F mutation was detected. He presented with recurrent adrenal infarction and developed aortic mural thrombosis and splenic infarction. We administered aspirin and performed cytoreductive therapy with hydroxyurea and anagrelide; however, the patient then went into heart failure resulting from coronary artery stenosis. We then added prasugrel to the list of medicines administered to manage his condition. Bilateral adrenal infarction is a very rare thrombotic event of essential thrombocythemia. CT and MRI were useful for making the diagnosis; however, we also had to rule out acute coronary syndrome or intestinal ischemia. Our patient presented with strong thrombotic diathesis, which prompted us to use dual antiplatelet therapy; however, further studies are needed to confirm the efficacy and safety of this treatment.

At 11 weeks of pregnancy, a 31-year-old woman presented with an anterior chest tumor and dyspnea. A computed tomography (CT) scan revealed a bulky tumor in the mediastinum that compressed the trachea. She underwent a CT-guided needle biopsy and was diagnosed with primary mediastinal large B cell lymphoma. She was initially treated with steroid pulse therapy, followed by vincristine-cyclophosphamide-prednisolone (VCP) therapy, which relieved her dyspnea. She was then treated with 8 cycles of rituximab-cyclophosphamide-doxorubicin-vincristine-prednisolone (R-CHOP) therapy at 13 weeks of pregnancy. The patient delivered her baby at 35 weeks and 6 days of pregnancy. Despite the preterm delivery and other than the low-birth weight, her baby was healthy. A positron emission tomography-CT scan showed that a complete metabolic response was achieved. Our case report suggests that steroid pulse and VCP therapy followed by R-CHOP therapy is safe and effective for patients with malignant lymphoma in their first trimester of pregnancy.

A 57-year-old man with high-risk myelodysplastic syndrome underwent umbilical cord blood transplantation. He began receiving steroids on day 14 for acute graft-versus-host disease, and experienced dizziness on day 75 during gradual dose reduction. Multiple hemorrhages were observed in the cerebrum, cerebellum, and brainstem. His bleeding increased, and he underwent a brain biopsy on day 91. Subsequently, he was diagnosed with central nervous system vasculitis (CNSV) on the basis of the observed aggregation of mature CD3⁺ lymphocytes around small vessels and vascular wall invasion by lymphocytes and macrophages. After receiving high-dose steroid therapy, cerebral hemorrhage stopped; however, dysphasia occurred on day 113 and the patient died of cerebral edema on day 128. Toxoplasma DNA and tachyzoites were detected in the brain biopsy specimen during additional examinations; therefore, we suspected that the toxoplasmosis was related to the onset of CNSV. CNSV is a rare, rapidly progressing disease that may present as a fatal post-transplantation central nervous system complication. Investigating the causes of CNSV, including CNSV associated with toxoplasmosis, is critically important for improving the prognosis of patients with CNSV.

A 63-year-old woman was admitted to our hospital to receive a fourth course of modified rituximab-ESHAP chemotherapy for relapsed primary breast diffuse large B-cell lymphoma. She developed hemophagocytic lymphohistiocytosis (HLH) 20 days after admission. Polymerase chain reaction (PCR) detected cytomegalovirus (CMV) DNA in her peripheral blood; therefore, she was diagnosed with CMV-associated HLH and consequently treated with foscarnet (FCN). Her general condition and pancytopenia soon improved, and the antiviral drug was stopped for 1 week. However, she suddenly became disoriented 10 days later, and this condition rapidly worsened. Cerebrospinal fluid (CSF) examination revealed an elevated white blood cell count with lymphocytic predominance and a high CMV DNA load, prompting a final diagnosis of CMV meningoencephalitis. We began intravenous combination therapy with FCN and ganciclovir (GCV), and her conscious state gradually improved. CMV DNA sequencing did not reveal drug resistance associated with mutations, and intravenous GCV was stopped for 1 week. FCN treatment was then continued until CMV DNA was no longer detected in her CSF samples via PCR. CMV meningoencephalitis is a rare neurological infection complicated with hematological malignancy in non-transplant patients and can be serious and life-threatening with a high mortality rate. This infection requires a differential diagnosis of consciousness impairment that develops in a patient with lymphoid malignancy during chemotherapy.

We managed a patient with acute myeloid leukemia (AML) who showed refractory ascites that developed in late-phase cord blood transplantation (CBT). The ascites obverted 5 months after CBT. The liver was atrophic, and serum hyaluronic acid was elevated at the onset, suggesting fibrotic changes in the liver. The ascites were transiently improved by cell-free and concentrated ascites reinfusion therapy (CART) and corticosteroid administration; however, the patient died from anasarca and recurrent AML 378 d after CBT. The etiology of the ascites is not well understood; therefore, additional studies on similar patients should be explored for proper management.

A 48-year-old Filipino woman underwent umbilical cord blood stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia under non-remission status. Left aqueous humor puncture was performed owing to the development of left eye pain and exacerbation of anterior eye chamber inflammation 72 days after the transplantation; this revealed the relapse of leukemia in the anterior chamber. Subsequently, the patient tested positive for peripheral blood minimal residual disease. Therefore, doctors should take note that anterior chamber disease may appear as a non-typical relapse of leukemia.

A 71-year-old man diagnosed with IgG-κ type multiple myeloma 11 years ago was treated with low doses of pomalidomide (POM, 1 mg/daily) and dexamethasone (20 mg/week) as the third-line of salvage regimen. The treatment was terminated 4 days later owing to the appearance of a severe skin rash, which had also occurred after previous treatment with lenalidomide. After 2 months, POM was readministered via an outpatient desensitization protocol under prednisolone administration. During five cycles of POM-treatment, no severe skin rash appeared, and partial remission was obtained even though the final POM dose was as low as 1 mg/day.