Publications by authors named "Jun-Ichi Tamaru"

A subset of patients with rheumatoid arthritis receiving methotrexate develop immune deficiencies and dysregulation-associated lymphoproliferative disorders. Patients with these disorders often exhibit spontaneous regression after MTX withdrawal; however, chemotherapeutic intervention is frequently required in patients with classic Hodgkin lymphoma arising in immune deficiency/dysregulation. In this study, we examined PD-L1 expression levels and 9p24.

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Article Synopsis
  • Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a newly recognized disease linked to immune deficiencies, highlighted in a case study of an 82-year-old man with throat pain and a history of rheumatoid arthritis.
  • Despite initial concerns about potential malignancies, cytological examinations consistently showed benign characteristics in the lymphoid cells, aiding in the diagnosis.
  • The study emphasizes that cytology is a valuable diagnostic method for distinguishing EBVMCU from malignant lymphoma, showcasing its utility in clinical settings.
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  • - Notch signaling is a crucial communication method between cells that influences how they develop and differentiate, relying on receptor-ligand interactions on cell surfaces.
  • - The study finds that overexpression of a protein called TM2D3, similar to a Drosophila protein, activates Notch1 by binding to it and enhancing its presence on the cell surface.
  • - Without TM2D3, Notch1 and Notch2 levels drop on the cell surface, leading to deficiencies in cell signaling and endocytosis in developing Drosophila embryos.
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Neuropil-like islands (NIs) are a histologic hallmark of glioneuronal tumors with neuropil-like islands (GTNIs), but GTNIs are presently not considered a homogeneous entity. The essence of GTNI is likely its glial component, and NIs are now considered aberrant neuronal differentiation or metaplasia. The case we report herein is a 41-year-old woman who was synchronously affected by two brain tumors: one was a glioblastoma (glioblastoma multiforme, GBM), of isocitrate dehydrogenase (IDH)-wild type, with NIs in the left parietal lobe, and the other was histologically a composite gangliocytoma (GC)/anaplastic ganglioglioma (GG) with NIs in the right medial temporal lobe.

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Compared with those involving the central nervous system, lymphomas involving the peripheral nervous system, namely neurolymphomatosis, are extremely rare. Neurolymphomatosis is classified as primary or secondary; the former is much rarer than the latter. Herein, we present an autopsied case of primary cauda equina lymphoma (PCEL), a type of primary neurolymphomatosis, with a literature review of autopsied cases of PCEL as well as primary neurolymphomatosis other than PCEL (non-PCEL primary neurolymphomatosis).

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The distribution and clinical impact of cell-of-origin (COO) subtypes of diffuse large B-cell lymphoma (DLBCL) outside Western countries remain unknown. Recent literature also suggests that there is an additional COO subtype associated with the germinal center dark zone (DZ) that warrants wider validation to generalize clinical relevance. Here, we assembled a cohort of Japanese patients with untreated DLBCL and determined the refined COO subtypes, which include the DZ signature (DZsig), using the NanoString DLBCL90 assay.

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Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a newly recognized disease entity characterized by EBV-positive atypical B-cell proliferation. EBVMCU is a localized self-limited disease that affects mucosa and skin, especially the oral cavity. EBVMCU develops in immunosuppressive patients, such as those with methotrexate (MTX)-administrated rheumatoid arthritis (RA).

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UTX/KDM6A, a histone H3K27 demethylase and a key component of the COMPASS complex, is frequently lost or mutated in cancer; however, its tumor suppressor function remains largely uncharacterized in multiple myeloma (MM). Here, we show that the conditional deletion of the X-linked Utx in germinal center (GC) derived cells collaborates with the activating Braf mutation and promotes induction of lethal GC/post-GC B cell malignancies with MM-like plasma cell neoplasms being the most frequent. Mice that developed MM-like neoplasms showed expansion of clonal plasma cells in the bone marrow and extramedullary organs, serum M proteins, and anemia.

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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%).

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Cancer antigen 125 (CA125) is one of the mucin family proteins and is a serum tumor marker for various tumors, such as ovarian cancer, endometrial cancer, pancreatic cancer, and bladder cancer. CA125 is used to distinguish between benign and malignant tumors, monitor the response to chemotherapy, and detect relapse after initial treatment. Recently, CA125 was reported to be involved in chemoresistance through the physical characteristics of mucin or by modifying the immune tumor-microenvironment.

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Background: The goal was to determine whether the addition of temozolomide (TMZ) to the standard treatment of high-dose methotrexate (HD-MTX) and whole-brain radiotherapy (WBRT) for primary central nervous system lymphoma (PCNSL) improves survival.

Methods: An open-label, randomized, phase III trial was conducted in Japan, enrolling immunocompetent patients aged 20-70 years with histologically confirmed, newly diagnosed PCNSL. After administration of HD-MTX, patients were randomly assigned to receive WBRT (30 Gy) ± 10 Gy boost (arm A) or WBRT ± boost with concomitant and maintenance TMZ for 2 years (arm B).

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Background: Chronic spinal epidural hematomas (SEHs) are rare clinical entities. SEH with vertebral scalloping is extremely rare, with only a few cases having been reported to date. We report a unique case of spontaneous chronic SEH in the lumbar spine with severe vertebral scalloping mimicking an epidural tumor.

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Primitive myxoid mesenchymal tumor of infancy (PMMTI) is a rare soft tissue sarcoma in childhood. We present the case of a newborn male who experienced a severe hemorrhage in utero from the tumor on the scalp. He died at the age of 24 hours owing to hemorrhagic shock.

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Article Synopsis
  • Laparoscopic surgery for malignant tumors can lead to port-site metastasis (PSM), which is the recurrence of cancer at the site of the trocar insertion.
  • A 42-year-old woman underwent emergency laparoscopic surgery for a suspected ovarian tumor, which was later diagnosed as a mucinous borderline tumor; however, she developed an undifferentiated carcinoma at the port site eight months later.
  • This case highlights unusual PSM with different histological findings than the original tumor, emphasizing the need for careful diagnosis and monitoring during and after surgery.
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Cholesterol is an essential plasma membrane lipid for the maintenance of cellular homeostasis and cancer cell proliferation. Free cholesterol is harmful to cells; therefore, excessive free cholesterol must be quickly esterified by acetyl-coenzyme A:cholesterol acetyltransferase (ACAT) and exported by scavenger receptor class B member I (SR-BI) or ATP-binding cassette protein A1 from specific cells such as macrophage foam cells, which contain cholesteryl ester-derived vacuoles. Many vacuoles are present in the cytoplasm of Burkitt lymphoma cells.

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The tumor microenvironment (TME) is a critical regulator of the development of malignant lymphoma. Therapeutics targeting the TME, especially immune checkpoint molecules, are changing the treatment strategy for lymphoma. However, the overall response to these therapeutics for diffuse large B-cell lymphoma (DLBCL) is modest and new targets of immunotherapy are needed.

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Intravascular large B-cell lymphoma (IVLBCL) is a rare lymphoma characterized by the selective growth of lymphoma cells within the lumen of vessels. We describe the case of a 69-year-old male who presented with marked pain in the left facial region. Gadolinium-enhanced magnetic resonance imaging revealed a swollen left trigeminal nerve (TN) and positron emission tomography/computed tomography demonstrated fluorodeoxyglucose-only uptake at the same site.

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Background: Desmoplastic fibroblastoma (also known as collagenous fibroma) is a benign, slowly growing soft-tissue tumor. Most desmoplastic fibroblastomas develop in the limbs, neck, or trunk. A mediastinal origin is quite rare.

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We compared the two methods of assessing CD30 protein expression in DLBCL and TCL specimens routinely employed at our hospital, immunohistochemistry (IHC) and flow cytometry (FCM), using the same clone of the anti-CD30 antibody (Ber-H2) in 123 patients with DLBCL and 28 patients with TCL. FCM was more sensitive than IHC, especially in cases with low expression. In three cases of TCL and two cases of DLBCL, there was discordance between these two methods.

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Next-generation sequencing of oral squamous cell carcinoma (OSCC) has revealed TP53 as the most frequently mutated gene in OSCC mutually exclusive with human papillomavirus infection. Oral epithelial dysplasia (OED) is defined as a precancerous lesion of OSCC by the current World Health Organization (WHO) classification; therefore, it is assumed that TP53 mutations occur in early precancerous conditions such as OED. Here, we conducted an integrated analysis of TP53, including whole coding sequencing of TP53, FISH analysis of the 17p13.

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Background: The prevalence of Lynch syndrome (LS)-associated DNA mismatch repair (MMR)-deficient bladder cancer (BC) has scarcely been investigated.

Methods: Immunohistochemistry for four MMR proteins (MLH1, MSH2, MSH6, and PMS2) was performed in formalin-fixed paraffin-embedded (FFPE) sections prepared from the resected specimens of 618 consecutive newly diagnosed BC cases. Genetic/epigenetic analyses were performed in patients displaying the loss of any MMR proteins in the tumor.

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The current World Health Organization (WHO) classification defines a new disease entity of high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements, making fluorescence in situ hybridization (FISH) screening for these genes mandatory. In addition, the prognostic significance of MYC expression was reported, with a cut-off value of 40%. However, interobserver discrepancies arise due to the heterogeneous intensity of MYC expression by immunohistochemistry.

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