Document Type: Original Paper
Tarbiat Modares University
1Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
2Department of Anatomy, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
3Department of Pathology, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran
Introduction: Ultraviolet (UV) radiation to the skin causes oxidative damage and causes cancer in the epidermis. There seems to be a relationship between the thickening of the skin layer and the carcinogenicity. The aim of this study was to establish a rare benign skin lesion of Trichoepithelioma in an animal model and to investigate the relationship between the radiation dose of ultraviolet waves with thickening of the skin layer resulting from high-frequency ultrasound images.
Materials and Methods: To investigate the skin damage process, 25 C57BL6 mice were irradiated with UVB (5 times a week for 9 weeks) with an energy density of 135, 270, 405, 540, 675, 810, 945, 1080 and 1215 J/m2, from the first week to the ninth week, respectively. The thickness of the skin layer was measured weekly by ultrasound images. The correlation between the thickness of the skin layer and the radiation energy density was analyzed by Pearson correlation analysis.
Results: The thickness of the skin layer showed a significant increase in the 7th week of exposure relative to zero-day during the injury process due to UV radiation (P˂0.05). Additionally, it showed a 38 % increase in the 7th week. The results showed a significant correlation coefficient of more than 0.97 between the thickness of the skin layer and the energy density of UV radiation. Microscopic sections in the long-term UV-irradiated group confirmed Trichoepithelioma.
Conclusion: Prolonged irradiation for 9 weeks produces an animal model of Trichoepithelioma.