Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of lymphoid malignancies. Several recent comprehensive genomic studies characterize the genomic alterations of each PTCL type and reveal the complexity and heterogeneity. The updated World Health Organization classification has precisely distinguished “lymphoma” from “lymphoproliferative disorder” and has included a new entity based on the tumor phenotypes. Although establishing the classifications based on genomic alterations has been difficult because of heterogeneity, the genomic alterations may support the diagnosis. Establishing genomic alterations that act as predictive markers for clinical courses and/or therapeutic targets is needed in future studies using genomic alteration information. Since patients with PTCL generally have poor prognosis, establishing the target and standard therapies is one of the major issues to be addressed. In addition to clinicopathological and genomic analyses, patient-derived xenograft models can provide these therapeutic strategies. Integration of analyzed data is considered to promote future PTCL studies, leading to improved PTCL prognosis.

Pregnancy with paroxysmal nocturnal hemoglobinuria (PNH) poses a high risk of thrombosis, maternal death, miscarriage, and premature infants. Eculizumab lowers complications for pregnancy with PNH. A proposed protocol for the management of pregnancy in women with PNH by The National Research Group on Idiopathic Bone Marrow Failure Syndrome (the Japanese Guideline) recommends patients to start eculizumab at an early stage of pregnancy if they have not been treated with eculizumab or continue eculizumab during pregnancy. A 31-year-old female with PNH who was transfusion-independent but had occasional hemolysis was treated with eculizumab after a missed abortion and soon conceived. During pregnancy, the patient had neither hemolysis nor thrombosis and gave birth to a healthy child without using heparin. Heparin was initiated soon after delivery and continued for six weeks because of the known high postpartum risk of thrombosis. No postpartum complications were observed. PNH is a rare disease with fewer cases of pregnancy reported. Hence, it is essential to accumulate cases of PNH with pregnancy to establish the validity of the Japanese Guideline.

Chronic active Epstein-Barr virus infection (CAEBV) is critical owing to lethal complications such as hemophagocytic lymphohistiocytosis (HLH), multiple organ failure, and malignant lymphoma. Here we present two cases of CAEBV who developed rapid and life-threatening disease progression after cytotoxic chemotherapy. Case 1: In a 34-year-old male, CAEBV recurred after 4-month remission obtained by initial therapy with etoposide, cyclosporine, and prednisolone. Accordingly, cord blood transplantation was planned. A day after administering high-dose melphalan as the conditioning, he developed respiratory failure, pancytopenia, and hyperferritinemia. He died 3 days later. Case 2: A 53-year-old female attained remission after initial therapy for CAEBV. After 1 month, she relapsed, and high-dose cytarabine (HDAC) was administered. A day after HDAC administration, she suddenly developed respiratory failure, which was followed by multiple organ failure. She died 3 days later. Thus, planned strategy for prompt allogeneic hematopoietic stem cell transplantation is necessary to prevent disease progression and control cytokinemia before cytotoxic chemotherapy for CAEBV.

An 80-year-old male was referred to our department for prolonged APTT (activated partial thromboplastin time) and subcutaneous hemorrhage. His medical history comprised alcoholic liver cirrhosis, hepatocellular carcinoma (HCC), and peripheral artery disease (PAD). For refractory HCC, he had received transcatheter arterial chemoembolization and was followed up regularly at our hospital. He underwent percutaneous transluminal angioplasty for PAD 10 months ago, and dual antiplatelet therapy with clopidogrel and cilostazol was initiated. Cilostazol was discontinued owing to subcutaneous hemorrhage 6 months ago. The prolonged APTT level, inhibitor pattern by cross-mixing test, and the presence of the inhibitor against factor VIII (449 Bethesda unit/ml) corroborated acquired hemophilia A (AHA). Thus, clopidogrel was discontinued for possible drug-induced AHA. After 4-week oral corticosteroid therapy, the APTT level recovered to normal. This case highlights two distinct features as follows: (1) possible relation to clopidogrel; and (2) despite extremely high titer of factor VIII inhibitor, his bleeding episodes were managed without antihemorrhagic agents. Here we present a case of clopidogrel-related AHA. Further accumulation of such cases is warranted to determine the potential correlation with clopidogrel and AHA.

A 51-year-old man underwent allogeneic bone marrow transplantation (BMT) for recurrent acute myeloid leukemia. Although the patient developed slight edema, pleural effusion, and cardiac effusion 6 months after BMT, his clinical condition improved with furosemide treatment. The patient was transfused with red blood cells for the management of anemia 8 months after BMT. He developed acute respiratory failure with pulmonary alveolar hemorrhage 80 min after the transfusion. He was diagnosed with transfusion-associated circulatory overload (TACO) due to the presence of acute pulmonary congestion and depressed left ventricular systolic function. Reduced circulatory load due to sufficient furosemide led to ventilator weaning 3 days later. Other causes of pulmonary alveolar hemorrhage were excluded, and the patient's condition improved by cardiac failure treatment only. This clinical course indicated that pulmonary alveolar hemorrhage would breakdown the blood vessels due to acute pulmonary congestion. Chemotherapy and prolonged anemia are high risks for cardiac failure in patients with hematological malignancies. Therefore, the possibility of cardiac failure is considered when patients with hematological malignancies have fluid retention, such as cardiac enlargement, edema, and pleural effusion. Moreover, the body fluids should be monitored before and after blood transfusion.

A 65-year-old woman was diagnosed with rheumatoid arthritis in 2010 and was treated with methotrexate (MTX). In 2012, she was diagnosed with sarcoidosis and underwent a follow-up therapy for mild peripheral neuropathy due to neurosarcoidosis. In 2018, she experienced primary splenic diffuse large B-cell lymphoma (DLBCL) and was diagnosed with sarcoidosis-lymphoma syndrome (SLS). MTX was discontinued, and six cycles of rituximab were administered combined with chemotherapy. Positron emission tomography combined with computed tomography performed 18 weeks after the last cycle of chemotherapy showed new abnormal fluoro-2-deoxy-D-glucose (FDG) uptake in the mediastinal and hilar lymph nodes and skeletal muscles. Sarcoidosis was suspected because of increased serum angiotensin-converting enzyme levels and magnetic resonance imaging findings in the lower limb muscles. However, pathological findings of DLBCL and sarcoidosis were not confirmed in the hilar lymph node biopsy. Therefore, malignant lymphoma can be distinguished from sarcoidosis using abnormal FDG uptake after chemotherapy for SLS.

We report three cases of POEMS syndrome treated with lenalidomide and dexamethasone who presented with peripheral neuropathy. All of them had markedly elevated serum vascular endothelial growth factor (VEGF) levels treated with lenalidomide and dexamethasone for severe peripheral neuropathy, which normalized serum VEGF levels and improved peripheral neuropathy. The standard treatment of POEMS syndrome has not been established, but has been effectively treated with high-dose chemotherapy with autologous stem cell transplantation. Newer agents currently used for plasma cell dyscrasias include bortezomib and immunomodulatory drugs, such as thalidomide and lenalidomide. A randomized controlled trial on thalidomide plus dexamethasone for POEMS syndrome showed reduced serum VEGF levels after therapy; however, the incidence of peripheral neuropathy, a well-known side effect of both thalidomide and bortezomib, increased. Lenalidomide is associated with lower incidence of peripheral neuropathy compared to thalidomide and bortezomib, making it a reasonable treatment option for POEMS syndrome.

Langerhans cell sarcoma (LCS) is a rare neoplastic proliferation of Langerhans cells with a poor prognosis. Owing to its rarity, standard treatment for LCS has not been established to date. Here, we report a case of LCS occurring in multiple lymph nodes in the right cervix in which remission is maintained by autologous hematopoietic stem cell transplantation (auto-HSCT) after surgical resection. A 58-year-old male presented with enlarged right submandibular lymph nodes. Positron-emission tomography/computed tomography (PET/CT) revealed multiple lymphadenopathies in his right cervix. We performed a lymph node biopsy, and he was diagnosed with LCS. We selected the CHOP regimen as the first-line chemotherapy; however, rapid disease progression was observed soon after the first cycle of the therapy. The neck dissection was performed on day 16 of the CHOP therapy. As the residual tumor was suspected, we started the second-line chemotherapy with a combination of etoposide, cisplatin, ifosfamide, and gemcitabine; complete remission was confirmed by PET/CT. Subsequently, the patient was administered high-dose chemotherapy with auto-HSCT. After 2 years of auto-HSCT, complete remission has been maintained. Although there is no report of auto-HSCT for LCS, it could be an effective therapeutic tool for the disease.

A 68-year-old female was diagnosed with follicular lymphoma (FL) grade 2, based on the excisional biopsy of her enlarged left cervical lymph node. Positron-emission tomography/computed tomography (PET/CT) revealed the ¹⁸F-fluoro-deoxyglucose-avid lesions in the sigmoid colon and at the fundus of the gallbladder, besides those in the left neck. A sigmoid colon polyp, which was endoscopically resected, proved histologically to be a well- to moderately-differentiated tubular adenocarcinoma with deep invasion into the submucosa. In addition, nodular lesions of the gallbladder were enhanced on dynamic CT, markedly suggesting gallbladder carcinoma. Among FL, colorectal cancer, and presumed gallbladder adenocarcinoma, FL was considered having the lowest priority of treatment because of its indolent nature and low tumor burden. We performed laparoscopic-assisted sigmoid colectomy, followed by gallbladder bed resection on the same day. Unpredictably, gallbladder lesions were histologically revealed to be FL. Often, FL involves extranodal sites such as the gastrointestinal tracts. However, the gallbladder involvement is extremely rare, and preoperative distinction from gallbladder adenocarcinoma remains challenging to date; this report discusses its characteristics along with the literature review. Furthermore, our case, in which another malignant neoplasm coexisted, needed histological identification of the gallbladder lesions to ascertain the therapeutic strategy.

A 65-year-old male was admitted for bladder and rectal dysfunction with lower-limb sensory disturbance. Although no abnormalities were detected on magnetic resonance imaging of the brain and spinal cord, an elevation in the serum anti-cytomegalovirus (CMV) -IgM level and pneumonia suggest viral meningomyelitis. However, steroid pulse and anti-CMV treatments did not resolve the patients' symptoms. Lung and skin biopsies revealed an invasion of atypical lymphoid cells into small vessels, consistent with intravascular large B-cell lymphoma (IVLBCL). Chemotherapy comprising R-CHOP and intrathecal administration of methotrexate resolved neurological complications quickly, and the patient remains in complete remission after 2 years. Notably, IVLBCL with cauda equina syndrome is highly rare.