1. Pathology Department, University Hospital “Dr. Jose E. Gonzalez” and Medical School of the Autonomous University of Nuevo Leon, Francisco I. Madero and Gonzalitos, 64460 Monterrey, NL, Mexico
2. Otolaryngology-Head and Neck Surgery Department, University Hospital “Dr. Jose E. Gonzalez” and Medical School of the Autonomous University of Nuevo Leon, Francisco I. Madero and Gonzalitos, 64460 Monterrey, NL, Mexico