Numerous canine papillomaviruses (CPVs) have been identified (CPV1–23). CPV1, 2, and 6 have been associated with inverted papillomas (IPs). We retrieved 19 IPs from 3 histopathology archives, and evaluated and scored koilocytes, inclusion bodies, giant keratohyalin granules, cytoplasmic pallor, ballooning degeneration, and parakeratosis. IHC targeting major capsid proteins of PV was performed, and CPV genotyping was achieved by PCR testing. Tissue localization of CPV DNA and RNA was studied by chromogenic and RNAscope in situ hybridization (DNA-CISH, RNA-ISH, respectively). IPs were localized to the limbs (50%), trunk (30%), and head (20%), mainly as single nodules (16 of 19). In 15 of 19 cases, immunopositivity was detected within the nuclei in corneal and subcorneal epidermal layers. PCR revealed CPV1 in 11 IPs and CPV2 DNA in 3 IPs. Overall, 14 of 17 cases were positive by both DNA-CISH and RNA-ISH, in accord with PCR results. A histologic score >5 was always obtained in cases in which the viral etiology was demonstrated by IHC, DNA-CISH, and RNA-ISH. IHC and molecular approaches were useful to ascertain the viral etiology of IPs. Although IHC is the first choice for diagnostic purposes, ISH testing allows identification of PV type and the infection phase. RNA-ISH seems a promising tool to deepen our understanding of the pathogenesis of different PV types in animal species.

已鉴定出许多犬乳头瘤病毒 (CPV) (CPV1-23)。CPV1、2 和 6 与倒置乳头状瘤 (IP) 相关。我们从 3 个组织病理学档案中检索了 19 个 IP，并对挖空细胞、包涵体、巨大的透明角质颗粒、细胞质苍白、气球样变性和角化不全进行了评估和评分。进行针对PV主要衣壳蛋白的IHC，并通过PCR检测实现CPV基因分型。通过显色和 RNAscope 原位杂交（分别为 DNA-CISH、RNA-ISH）研究 CPV DNA 和 RNA 的组织定位。IP 位于四肢 (50%)、躯干 (30%) 和头部 (20%)，主要为单个结节 (16 个，共 19 个)。19 例中有 15 例在角膜和角膜下表皮层的细胞核内检测到免疫阳性。PCR 揭示了 11 个 IP 中的 CPV1 和 3 个 IP 中的 CPV2 DNA。全面的，17例中有14例DNA-CISH和RNA-ISH均呈阳性，与PCR结果一致。在 IHC、DNA-CISH 和 RNA-ISH 证实病毒病因的病例中，组织学评分总是 >5。IHC 和分子方法有助于确定 IP 的病毒病因。尽管 IHC 是诊断目的的首选，但 ISH 测试可以识别 PV 类型和感染阶段。RNA-ISH 似乎是一种很有前途的工具，可以加深我们对动物物种中不同 PV 类型发病机制的理解。尽管 IHC 是诊断目的的首选，但 ISH 测试可以识别 PV 类型和感染阶段。RNA-ISH 似乎是一种很有前途的工具，可以加深我们对动物物种中不同 PV 类型发病机制的理解。尽管 IHC 是诊断目的的首选，但 ISH 测试可以识别 PV 类型和感染阶段。RNA-ISH 似乎是一种很有前途的工具，可以加深我们对动物物种中不同 PV 类型发病机制的理解。