Browsing by Subject "molecular genetics"

Now showing 1 - 3 of 3
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    Distinct Mutational Landscape of Inverted Urothelial Papilloma
    (Wiley, 2019-09) Akgul, Mahmut; MacLennan, Gregory T.; Cheng, Liang; Pathology and Laboratory Medicine, School of Medicine
    A recent study has identified gene mutations involving the MAPK/ERK pathway, particularly the HRAS gene, in all inverted urothelial papillomas (IUPs), in the absence of pathway mutations in TERT promoter, FGFR3, and TP53/RB1genes. Neither recurrence nor progression was observed in IUPs. These data support several longstanding hypotheses: (1) IUPs are benign and do not recur or progress; (2) they harbor mutations that are different from those of urothelial carcinoma; and (3) they arise through different molecular mechanisms than low‐ or high‐grade urothelial carcinoma. As the most critical differential diagnosis in this context is inverted‐type urothelial carcinoma, more comprehensive studies are needed to compare and contrast these entities.
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    Fluorescence in situ Hybridization in Surgical Pathology: Principles and Applications
    (Wiley, 2017) Cheng, Liang; Zhang, Shaobo; Wang, Lisha; MacLennan, Gregory T.; Davidson, Darrell D.; Department of Pathology and Laboratory Medicine, IU School of Medicine
    Identification of recurrent tumour-specific chromosomal translocations and novel fusion oncogenes has important diagnostic, therapeutic and prognostic implications. Over the past decade, fluorescence in situ hybridization (FISH) analysis of tumour samples has been one of the most rapidly growing areas in genomic medicine and surgical pathology practice. Unlike traditional cytogenetics, FISH affords a rapid analysis of formalin-fixed, paraffin-embedded cells within a routine pathology practice workflow. As more diagnostic and treatment decisions are based on results of FISH, demand for the technology will become more widespread. Common FISH-detected alterations are chromosome deletions, gains, translocations, amplifications and polysomy. These chromosome alterations may have diagnostic and therapeutic implications for many tumour types. Integrating genomic testing into cancer treatment decisions poses many technical challenges, but rapid progress is being made to overcome these challenges in precision medicine. FISH assessment of chromosomal changes relevant to differential diagnosis and cancer treatment decisions has become an important tool for the surgical pathologist. The aim of this review is to provide a theoretical and practical survey of FISH detected translocations with a focus on strategies for clinical application in surgical pathology practice.
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    Müllerian Adenosarcoma of the Urinary Bladder: Clinicopathologic and Immunohistochemical Features with Novel Genetic Aberrations
    (Elsevier, 2017-04) Sanfrancesco, Joseph; Williamson, Sean R.; Kum, Jennifer B.; Zhang, Shaobo; Wang, Mingsheng; Lopez-Beltran, Antonio; Montironi, Rodolfo; Gardner, Thomas A.; Cheng, Liang; Department of Pathology and Laboratory Medicine, IU School of Medicine
    Müllerian adenosarcoma is a biphasic neoplasm most commonly of the uterus and less frequently of the ovary. It has been rarely described to occur in other sites such as peritoneum and liver. In this study, we report the clinicopathologic, immunohistochemical and molecular features of a primary müllerian adenosarcoma of the urinary bladder in a 62-year-old woman. To our knowledge, this is the first report of müllerian adenosarcoma primary to the urinary bladder in the literature. Light microscopy showed a biphasic epithelial and stromal tumor with benign-appearing glands surrounded by endometrial-type stroma that is densely cellular with increased mitotic figures. The stroma surrounding the glands is more cellular than the intervening areas, which are more loose and edematous. Immunohistochemistry profile included positive staining for Pax2/8 within the glands, for CD10 and WT-1 within the spindled stroma, and for estrogen and progesterone receptors in both. Staining for desmin, GATA3, p63, and human papilloma virus (HPV) is negative. Molecular analyses identified mutations in AKT1 E17K, FLT3 D835N, KRAS G12D and HRAS G12S. These novel molecular aberrations have yet to be reported in the medical literature. X chromosome inactivation analysis revealed a clonal pattern in the stromal component and a non-clonal pattern in the epithelial component. Currently, the patient is disease/recurrence-free after regular follow-up of approximately 84 months. This case represents the first reported diagnosis of müllerian adenosarcoma arising in the urinary bladder with extensive clinicopathologic, immunohistochemical, and molecular analyses.