title: Low prevalence of Merkel cell polyomavirus with low viral loads in oral and maxillofacial tumours or tumour-like lesions from immunocompetent patients: Absence of Merkel cell polyomavirus-associated neoplasms.
abstract: It was recently demonstrated that ~80% of Merkel cell carcinomas (MCCs) harbour a novel polyomavirus, Merkel cell polyomavirus (MCPyV). MCPyV has been detected in various human tissue samples. However, previous studies on the prevalence of MCPyV in oral tumours or tumour-like lesions are incomplete. To address this issue, we measured MCPyV DNA quantity using quantitative polymerase chain reaction (qPCR) in 327 oral tumours or tumour-like lesions and 54 jaw tumours or cyst lesions from 381 immunocompetent patients, as well as in 4 oral lesions from 4 immunosuppressed patients. qPCR revealed a low MCPyV prevalence (25/381, 6.6%) with low viral loads (0.00024-0.026 copies/cell) in oral and maxillofacial tumours and tumour-like lesions from immunocompetent patients. The prevalence was 7/176 (4.0%) in invasive squamous cell carcinomas (SCCs) [2/60 (3.33%) SCCs of the tongue, 4/52 (7.7%) SCCs of the gingiva and 1/19 (5.3%) SCCs of the floor of the mouth], 1/10 (10%) in dysplasias, 1/5 (20%) in adenocarcinomas, 2/13 (15.4%) in adenoid cystic carcinomas, 1/10 (10%) in non-Hodgkin's lymphomas, 3/10 (30%) in lipomas, 3/5 (60%) in neurofibromas, 1/3 (33.3%) in Schwannomas, 2/12 (16.7%) in Warthin's tumours, 2/11 (18.2%) in pyogenic granulomas, 1/14 (7.1%) in radicular cysts and 1/12 (8.3%) in ameloblastomas. The prevalence in lesions from immunosuppressed patients (1/4, 25%) was higher compared with that in lesions from immunocompetent patients (25/381, 6.6%), but the difference was not statistically significant. To the best of our knowledge, this study was the first to report prevalence data of MCPyV in tumours and cysts of the jaws (2/54, 3.7%). These data indicated absence of MCPyV-related tumours or tumour-like lesions in the oral cavity and jaws and suggested that the detected MCPyV DNA was derived from non-neoplastic background tissues with widespread low-level MCPyV infection.
authors.affiliation: Division of Oral and Maxillofacial Biopathological Surgery, Department of Medicine of Sensory and Motor Organs, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan; Division of Molecular Pathology, Department of Pathology, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Tanio
authors.affiliation: Division of Molecular Pathology, Department of Pathology, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Matsushita
authors.affiliation: Division of Molecular Pathology, Department of Pathology, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kuwamoto
authors.affiliation: Department of Anatomic Pathology, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8504, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Horie
authors.affiliation: Division of Oral and Maxillofacial Biopathological Surgery, Department of Medicine of Sensory and Motor Organs, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Isamu
authors.initials: I
authors.lastname: Kodani
authors.affiliation: Division of Molecular Pathology, Department of Pathology, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Murakami
authors.affiliation: Division of Oral and Maxillofacial Biopathological Surgery, Department of Medicine of Sensory and Motor Organs, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ryoke
authors.affiliation: Division of Molecular Pathology, Department of Pathology, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hayashi
keywords: Merkel cell polyomavirus; jaw tumour; oral cavity tumour; quantitative polymerase chain reaction