Thrombocytopenia is a relatively common complication in pregnancy, with a reported frequency of 7%-11%. The causes of this condition are diverse, although the most common etiology is gestational thrombocytopenia (GT) (70%-80%), followed by HELLP syndrome and immune thrombocytopenia (ITP). To investigate the clinical features of thrombocytopenia during pregnancy, we conducted a retrospective analysis of 69 women at our center with 91 pregnancies in which the platelet count was below 100×10⁹/l. There were 38 cases in women with a prior diagnosis of thrombocytopenic diseases such as ITP or an inherited platelet disorder. In the remaining 53 cases, a diagnosis could be made only after delivery. We analyzed the disease course, maternal and perinatal characteristics, platelet count fluctuations, and pregnancy outcomes. The final diagnosis was GT in 38, ITP in 14, and other causes in 1. To distinguish between GT and ITP is not always feasible and can sometimes only be performed based on postpartum changes in the platelet count. In pregnant women with thrombocytopenia, careful follow-up of platelet count fluctuations after delivery is crucial to distinguish ITP from GT.

An 89-year-old woman was admitted to our hospital owing to liver dysfunction and ascites. Enhanced computed tomography (CT) revealed hepatomegaly and heterogeneous density in the liver. 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) /CT revealed diffuse accumulation of FDG throughout the liver. Histopathology of a biopsy specimen revealed hepatic mucosa-associated lymphoid tissue (MALT) lymphoma. Complete remission (CR) was achieved with two cycles of rituximab, pirarubicin, cyclophosphamide, vincristine, and prednisolone. Because a second CT demonstrated liver cirrhosis and a test for anti-mitochondrial antibody was positive, liver biopsy was repeated, and pathological examination confirmed primary biliary cholangitis (PBC). The lymphoma recurred after 18 months and was treated with rituximab, which again resulted in CR. Over the subsequent 7 years, the patient had no liver dysfunction or recurrent lymphoma. Interestingly, despite the underlying PBC, liver dysfunction in this case appeared only with the MALT lymphoma.

A 61-year-old man was admitted to our hospital with fever and massive leukocytosis. A bone marrow smear revealed an increased density of myeloid cells in various stages of maturation as well as dysplasia in the neutrophils. There was no proliferation of blasts, eosinophils, or basophils. Genomic analysis of the bone marrow cells revealed no detectable abnormalities associated with myeloproliferative neoplasms, including BCR-ABL1. Therefore, the patient was diagnosed with atypical chronic myeloid leukemia (aCML). Chromosomal analysis revealed the presence of 1-17 double minute chromosomes (dmin) in 20 of 20 tumor cells examined. Multiple MYC signals were detected via interphase fluorescence in situ hybridization, indicating MYC gene amplification in the dmins. Three months after the oral administration of hydroxyurea, leukocytosis reoccurred. Therefore, induction therapy followed with umbilical cord blood transplantation was performed. However, MYC signals remained detectable in the bone marrow sample obtained immediately after neutrophil engraftment, indicating the presence of residual tumor cells. To the best of our knowledge, this is the first case report of aCML with dmin gene amplification, suggesting that the dmin MYC amplification exacerbated the patient's disease.

A 51-year-old man with a 9-month history of narrowing of visual fields and papilledema was admitted to the Department of Neurosurgery. Upon admission, glycerol was intravenously administered and heparin flushes were initiated to maintain intravenous access. Brain MRI revealed right transverse and sigmoid sinus thrombosis on hospital day 2, and the patient was treated with unfractionated heparin. On hospital day 9, the patient had a seizure and impaired mental status. Moreover, on hospital day 10, the platelet count decreased to less than half compared with that documented upon admission. The patient was then switched from heparin to argatroban because thrombosis exacerbation due to heparin-induced thrombocytopenia (HIT) was suspected. Despite negative IgG-specific chemiluminescent immunoassay for anti-platelet factor 4 (PF4) /heparin antibodies, positive functional assay led to the diagnosis of HIT. Warfarin was initiated and the platelet count was restored. Because maintaining the patient's PT-INR within the therapeutic range was difficult probably due to concomitant antimicrobial administration for complicating pneumonia, anticoagulation was switched to rivaroxaban. No bleeding or thrombotic complications developed. Thus, the presentation and clinical course should be considered for an accurate diagnosis of HIT. This is particularly important when the immunological assay is negative for anti-PF4/heparin antibodies. Furthermore, anticoagulation with rivaroxaban can be useful in the management of the subacute phase of HIT.

The central nervous system (CNS) is rarely involved in plasma cell neoplasms (PCN), especially in patients with advanced disease, harboring poor prognostic chromosomal abnormalities. The prognosis after development of CNS is poor, with a median survival of 2-6 months. Here, we present a 56-year-old woman with isolated CNS relapse of plasma cell leukemia who was admitted to our hospital with back pain, thigh pain, and dysuria. Morphological examination of the cerebrospinal fluid (CSF) confirmed the presence of relapsed plasma cell leukemia, whereas active myeloma lesions were not detectable outside the CNS. Her symptoms did not improve with high doses of methotrexate or intrathecal chemotherapy. However, one cycle of combination therapy with lenalidomide and dexamethasone led to the improvement in clinical symptoms, with complete response seen in the CSF morphology. After 13 cycles, she developed a hematological relapse but maintained complete response in the CSF. The efficacy of lenalidomide in CSF PCN was sporadically reported, and the CNS penetrance of lenalidomide was demonstrated in animal models; however, its efficacy in CNS PCN has not been established. The current case supports the efficacy of combination therapy with lenalidomide as a new therapeutic strategy for CNS PCN.

A 67-year-old male was referred to our hospital because of anemia, thrombocytopenia, and massive ascites. A diagnosis of systemic mastocytosis was made based on the observation of many mast cells in his bone marrow, elevated serum tryptase levels, and the presence of c-kit point mutation Asp816Val. Dasatinib and cladribine were ineffective, and a large volume of ascites was removed approximately every 3 days. Then, following an asthma attack, the patient was treated with pranlukast, a leukotriene receptor antagonist (LTRA). After LTRA treatment initiation, the frequency of ascites drainage decreased, and no puncture was necessary from the 10th day after the start of LTRA. Interferon α (IFN-α) was administered from the 15th day after the start of LTRA. Thereafter, his anemia and thrombocytopenia gradually improved, the ascites disappeared, the mast cells in his bone marrow were significantly reduced, and the Asp816Val mutation disappeared. Because persistent monocytosis was evident, he was suspected of chronic myelomonocytic leukemia but has not been diagnosed and is undergoing watchful waiting. This was considered to be a rare case of refractory ascites in which IFN-α was effective and LTRA might have been beneficial.

In March 2009, a 17-year-old woman was first diagnosed with acute myelogenous leukemia and myelodysplasia-related changes. She underwent chemotherapy and allogeneic hematopoietic stem cell transplantation, which resulted in complete remission. However, she experienced relapse, and remission was achieved each time with repeated transplantation. In September 2014, a human leukocyte antigen (HLA)-haploidentical transplantation, which was the fifth allogeneic transplantation, was performed to treat the third relapse. Platelet transfusion refractoriness, hemolytic anemia with schistocytes, and renal dysfunction were observed from approximately the day of engraftment; therefore, transplantation-associated thrombotic microangiopathy (TA-TMA) was diagnosed. Recombinant human soluble thrombomodulin (rTM) was administered, and fresh-frozen plasma (FFP) was infused; this resulted in gradual improvement of TA-TMA. Treatment with rTM and FFP was discontinued on the 70th day after transplantation. Because the HLA-haploidentical transplantation was the fifth allogeneic transplantation, the risk of aggravation of TA-TMA was very high. Combined treatment with rTM and FFP, however, resulted in improvement of TA-TMA. Further investigation of similar cases is necessary for clarifying the usefulness of rTM for TA-TMA.

A 72-year-old man was hospitalized because of thrombocytopenia (0.5×10⁴/µl) and anemia. The bone marrow test result revealed excessive numbers of megakaryocytes and no platelet adhesion. Furthermore, platelet-associated immunoglobulin G levels were high, and he was tested positive for Helicobacter pylori antibody. On the basis of these findings, immune thrombocytopenia was diagnosed. The patient was initially treated with eradication therapy; prednisolone, 20 mg/day (0.5 mg/kg) and a thrombopoietin receptor agonist 12.5 mg/day. During the course of treatment, the anemia worsened. Detailed examination revealed marked prolongation of activated partial thromboplastin time and inhibition of factor VIII activity. Therefore, he was diagnosed with acquired hemophilia A. Although extensive muscle hemorrhage had occurred, hemostatic therapy comprising intensification of the immunosuppressive therapy and administration of recombinant activated factor VII resulted in successful hemostasis. As the treatment progressed, inhibition of factor VIII recurred temporarily; however, immunosuppressive therapy was continued. No recurrence was observed even after 1 year of the onset of both diseases.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) in the elderly was revised from the category EBV-positive DLBCL not otherwise specified in WHO 2017. The prognosis of this lymphoma is very poor. We report a case of an 82-year-old woman diagnosed with gastric EBV-positive DLBCL (WHO 2008). Gastroduodenoscopy revealed multiple ulcers and fold thickening. She was followed-up without any treatment because of her old age. Repeat endoscopy one year and eight months later revealed a single ulcer with no lymphoma cells found in a biopsy specimen. Two years later, the lesion had spontaneously disappeared.