Evaluation of the chicken embryo chorioallantoic membrane model for laryngeal tumor transplantation
The laryngeal squamous cell carcinoma is the second common malignant tumor of the respiratory tract and together with recurrent respiratory papillomas represents the most common tumors of the larynx. Many experimental models are used to study the morphology of malignant tumors. The chicken chorioallantoic membrane (CAM) model is one of them. The CAM has all the nutrition needed for the piece of the transplanted tumor to survive. The aim of this study was to investigate whether the laryngeal papilloma and the laryngeal squamous cell carcinoma tissues transplanted on the chick CAM survive with their main histological features, and to determine the morphological changes of the CAM with different transplants. For the preparation of the CAM, fertilized hen eggs were put into an incubator for 3 days. Then the windows in the shell were opened. The fresh samples of tumors were transplanted on the CAM on the 7th day of incubation. After 3 days after transplantation the CAM with onplants were excised and fixed in the 10% formalin solution. Morphological changes in the control CAM and in the CAM with tumor onplants were observed using the digital camera on the OLYMPUS microscope. The results showed that the CAM with the laryngeal squamous cell carcinoma onplant was distinctly thicker than that of the control group and than the CAM with the papilloma onplant; the chorionic epithelium was thickened and appeared stratified of up to 5–6 layers and in some locations squamous keratinized; the mesenchymal cells were densely arranged under the tumor transplants. We observed that morphological changes in the thickness of the CAM and the chorionic epithelium were more obvious in the CAM under the carcinoma transplants. After 72 hours of the tumor tissue transfer onto the membrane, the tumor cells retained their vitality and also their influence on the CAM tissues could be observed.