Aims Sinonasal inverted papillomas (SIP) and sinonasal squamous cell carcinomas (SNSCC) are sinonasal tumors with unclear etiology and pathogenesis. Epstein-Barr virus (EBV) has been detected in these tumors but information concerning their association is still limited. This study aimed to investigate the prevalence in, and association of EBV infection with SIP and SNSCC in northeastern Thailand. Methods DNA was extracted from 226 formalin-fixed, paraffin-embedded tissues including 80 nasal polyps (NP; the control group), 64 SIP and 82 SNSCC samples. Presence of EBV in these tissues was investigated using real-time PCR and their localization within tissues was confirmed using in situ hybridization (ISH). Characteristics of patients and the association of EBV prevalence with sinonasal tumors were analyzed. Results SIP and SNSCC were frequently found in people aged > 50 years and more often in males than in females (3:1 ratio). EBV infection was detected in 33.75, 64.06 and 37.80% of NP, SIP and SNSCC tissues, respectively, by real-time PCR. There was a statistically significant association between EBV infection and SIP (odds ratio [OR] = 3.52). This was not the case for SNSCC when compared to the NP group (OR = 1.83). Interestingly, EBV infection tended to be associated with inflammation and dysplasia in SIP. In SNSCC, EBV was mostly found in samples with undifferentiated or poorly differentiated cell types as well as in recurrent cases and lymph-node metastasis. Using ISH, EBV was detected only in infiltrating lymphocytes within the tumor stroma, not in the tumor epithelial cells. Conclusions Infiltrating lymphocytes containing EBV in the tumor microenvironment might enhance tumorigenesis of SIP and SNSCC. The mechanism by which EBV promotes development of SIP and SNSCC needs to be elucidated in the future.

中文翻译：

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泰国东北部人群中 Epstein-Barr 病毒感染与鼻窦内翻性乳头状瘤和鼻窦鳞状细胞癌的患病率和相关性

目的 鼻窦内翻性乳头状瘤（SIP）和鼻窦鳞状细胞癌（SNSCC）是病因和发病机制不明确的鼻窦肿瘤。已在这些肿瘤中检测到 Epstein-Barr 病毒 (EBV)，但有关其关联的信息仍然有限。本研究旨在调查泰国东北部 EBV 感染与 SIP 和 SNSCC 的患病率及其相关性。方法从福尔马林固定、石蜡包埋的226个组织中提取DNA，包括80个鼻息肉（NP；对照组）、64个SIP和82个SNSCC样本。使用实时 PCR 研究这些组织中 EBV 的存在，并使用原位杂交 (ISH) 确认它们在组织内的定位。分析了患者的特征以及 EBV 患病率与鼻窦肿瘤的关系。结果 SIP 和 SNSCC 常见于 > 50 岁的人群中，男性多于女性（比例为 3:1）。通过实时PCR，分别在33.75、64.06和37.80%的NP、SIP和SNSCC组织中检测到EBV感染。EBV 感染与 SIP 之间存在统计学上的显着关联（优势比 [OR] = 3.52）。与 NP 组相比，SNSCC 的情况并非如此（OR = 1.83）。有趣的是，EBV 感染往往与 SIP 中的炎症和发育异常有关。在 SNSCC 中，EBV 主要存在于未分化或分化差的细胞类型以及复发病例和淋巴结转移的样本中。使用 ISH，仅在肿瘤基质内的浸润淋巴细胞中检测到 EBV，而不在肿瘤上皮细胞中检测到。结论在肿瘤微环境中浸润含有EBV的淋巴细胞可能增强SIP和SNSCC的肿瘤发生。EBV 促进 SIP 和 SNSCC 发展的机制有待进一步阐明。