An Experimental Model of Human Recurrent Respiratory Papillomatosis: A Bridge to Clinical Insights.

OBJECTIVES/HYPOTHESIS: To investigate the growth pattern of recurrent respiratory papilloma (RRP) implants on chicken embryo chorioallantoic membranes (CAMs) and to evaluate possible associations between the clinical course of the disease and the behavior of experimentally implanted RRP tumors.

STUDY DESIGN: Experimental study.

METHODS: Fresh 172 RRP tissue samples from 12 patients were implanted onto chick embryo CAMs. Morphological and morphometric analysis of the experimental CAM and chorionic epithelium was performed. The microvascular network of the CAM with the RRP implant was investigated under the effect of fluoresceinated anionic dextran. The peculiarities of the clinical course of the disease were evaluated.

RESULTS: The implanted RRP tissue samples survived on CAMs in 86% of cases, retaining their essential morphologic characteristics and proliferative capacity of the original tumor. Implants induced thickening of both the CAM and the chorionic epithelium, but none of the RRP implants crossed the basement membrane of the hosting CAM. A "crawling film" of acellular material with newly formed papilloma sprouts located on the outer chorionic epithelium of the CAM was detected. Direct association between a recurrence rate of RRP and the number of newly formed papilloma sprouts around the implanted tumor on CAMs was revealed.

CONCLUSION: The chicken embryo CAM-based model is appropriate for investigations of RRP and facilitates the understanding of tumor biology and the clinical course of the disease, thus providing the basis for further research and acceleration of the identification and development of new specific therapeutic compounds that limit the spread and recurrence of RRP.

LEVEL OF EVIDENCE: N/A Laryngoscope, 2020.