• Journal of Yeungnam Medical Science
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• v.34 no.2
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• pp.293-297
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• 2017

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor that is highly aggressive in nature and indolent in progression. The common risk factors for MCC are senility, prolonged exposure to sunlight, and immune deficient states. Moreover, Merkel cell polyomavirus has recently been characterized to be significantly associated with pathogenesis of MCC, including the expression of Cytokeratin 20 (CK20). Diagnosis is often difficult since histopathological results require a number of differential diagnoses through immunohistochemical (IHC) stains with other cutaneous malignancies. A 67-year-old man presented with a solitary dome-shaped erythematous round mass on the left upper arm for 2 months. Biopsy and IHC studies revealed findings consistent with Merkel Cell Carcinoma of neuroendocrine origin. Common IHC stains usually confirm positive findings for CK20, which is also recognized as the key component in making the diagnosis. We present a CK20 negative MCC in light of expanding the knowledge of unusually stained IHC results in MCC.

• Microbiology and Biotechnology Letters
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• v.51 no.2
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• pp.135-146
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• 2023

Viral oncology is focused on understanding the relationship between cancer and viruses, which are known to play a role in the development of certain types of cancer. Approximately 15-20% of human cancers are believed to be caused by oncogenic viruses, and as a result, there is significant interest in understanding how these viruses contribute to cancer development. There are several viruses that have been linked to cancer, including human papillomavirus, hepatitis B and C virus, Epstein-Barr virus, human T-cell lymphotropic virus type 1, Kaposi's sarcoma-associated herpesvirus, and Merkel cell polyomavirus. Each of these viruses is associated with different types of cancer, and the mechanisms by which they contribute to cancer development are diverse. This article discusses these mechanisms as well as current and future strategies for preventing and treating virus-associated cancers with the goal of presenting a thorough review of the current state of knowledge in viral oncology and to highlight the importance of continued research in this field.