Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 57 10 2020 04 22 575 580 Sadra Masali Dentist, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Rosa Miri Department of Pathology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. AND Cancer Institute Pathology Lab, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. Mojgan Alaeddini Dental Research Center, Tehran University of Medical Sciences, Tehran, Iran. AND Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Shahroo Etemad-Moghadam Dental Research Center, Tehran University of Medical Sciences, Tehran, Iran. AND Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. Donia Sadri Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Fatemeh Shahsavari Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. 2019 05 06 2019 12 24 Despite the similarities between oral and esophageal squamous cell carcinomas (SCCs), the survival rate of this cancer is relatively low in the esophagus compared to the oral cavity. To our knowledge, mast cells and angiogenesis have not been simultaneously compared between oral and esophageal SCCs. However, they have been separately evaluated in each of these locations with conflicting results. Therefore, the aim of this study was to assess and compare mast cell count and microvessel density between SCCs of the esophagus and oral cavity. A total of 46 oral and esophageal SCCs (23 of each) were stained immunohistochemically and histochemically with CD31 and methylene blue, respectively. Statistical analysis was performed using t-test, one-way ANOVA, and Pearson correlation analysis. Microvessel density was significantly higher in oral compared to esophageal tumors (P=0.02). Conversely, esophageal SCCs showed significantly higher mast cell counts than that of oral neoplasms (P=0.04). Pearson correlation analysis showed no association between these two factors in either oral SCC (P=0.51) or esophageal SCC (P=0.34). A significant difference between mean mast cell count and microvessel density in oral and esophageal SCC may be related to inherent differences in the tissues of origin and might, to some extent, be responsible for the different biological behaviors of these cancers. https://acta.tums.ac.ir/index.php/acta/article/view/7860 https://acta.tums.ac.ir/index.php/acta/article/download/7860/5324