Publications by authors named "Mitsuhiro Nakamoto"

Background: Primary angiosarcomas of the breast are rare and highly aggressive. We herein report a rare case of multiple angiosarcomas detected concurrently in both breasts.

Case Presentation: A 49-year-old woman visited a doctor after noticing a lump in her right breast.

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Pancreatic cancer is still one of the most lethal malignancies in the world, and a more thorough understanding of its detailed pathogenetic mechanisms and the development of more effective therapeutic strategies are urgently required. Pancreatic ductal adenocarcinoma (PDA), the most common type of pancreatic cancer, is characterized by consistent genetic abnormalities such as point mutations in the Kirsten rat sarcoma viral oncogene homolog (KRAS) and in the tumor suppressor protein p53 (TP53) genes. Alterations in intracellular core signal pathways have also been shown to induce the development or progression of PDA.

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Background: Phosphaturic mesenchymal tumors (PMTs) are rare neoplasms that are often associated with tumor-induced osteomalacia (TIO) due to excessive serum levels of fibroblast growth factor 23 (FGF23). PMTs share overlapping histologic features with other types of tumors; thus, accurate pathological diagnosis may be challenging. We performed an immunohistochemical examination of FGF23 expression in PMTs and other types of tumors, together with pertinent molecular analyses.

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Familial adenomatous polyposis is associated with a high incidence of malignancies in the upper gastrointestinal tract (particularly ampullary adenocarcinomas). However, few reports have described a correlation between familial adenomatous polyposis and gallbladder neoplasms. We present a case of a 60-year-old woman with familial adenomatous polyposis who presented with an elevated mass in the neck of the gallbladder (measuring 16 mm × 8 mm in diameter) and multiple small cholecystic polyps.

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Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal human malignancies and is associated with a variety of molecular abnormalities. Although WNT signaling through its canonical/non-canonical pathways is one of the major factors involved in oncogenesis or progression of PDA, the prognostic significance of WNT signaling still remains poorly investigated. In this study, the status of the WNT signaling pathways was immunohistochemically analyzed in 101 PDAs, and its potential association with patient postoperative survival was assessed.

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Ewing sarcoma (ES) is a high-grade malignant neoplasm primarily affecting children and young adults. The diagnosis of ES is often difficult because of its broad differential diagnosis comprising a diverse group of small round cell tumors (SRCTs). Although the identification of tumor type-specific fusion genes by molecular testing is the gold standard for the diagnosis of ES, such approaches are not always available in a routine pathology practice.

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Context: Somatostatinoma is a rare neoplasm of the pancreas. Preoperative diagnosis is often difficult.

Case Report: We report a 72-year-old woman with a pancreatic head tumor measuring 37 mm in diameter, and enlargement of the lymph nodes on the anterior surface of the pancreatic head and the posterior surface of the horizontal part of the duodenum.

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Lipoblastoma is a distinct benign fatty tumor composed of adipocytes, lipoblasts, and primitive mesenchymal cells with a myxoid stroma. Lipoblastoma harbors characteristic fusion genes involving the PLAG1, resulting in aberrant expression of PLAG1. However, the nature of the primitive mesenchymal cells remains obscure.

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Article Synopsis
  • - Serious Cystadenoma (SCA) of the pancreas is typically benign and monitored, but in this case, a woman required surgery due to difficulties in diagnosing it from a similar condition called IPMN.
  • - A 58-year-old female patient with ovarian thecoma and Meigs syndrome had a cyst in the pancreas that grew from 2.4 cm to 3.5 cm over 14 months, prompting concerns about its nature.
  • - After surgery, the cyst was diagnosed as SCA based on specific tissue characteristics confirmed by staining techniques, and the patient's ascites were likely a result of pressure from her underlying condition.
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Liposarcomas are a representative group of soft tissue sarcomas with variably hampered adipogenesis, which is most exemplified by its dedifferentiated subtype. However, the factor(s) responsible for inhibiting adipocyte differentiation remains unknown. A recent gene expression profiling study identified several unique genes that were highly expressed in dedifferentiated liposarcoma, and the gene encoding calreticulin (CALR), a major Ca(2+)-buffering protein that can inhibit adipocyte differentiation, was found to be overexpressed.

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