Abstract
BACKGROUND: Lung cancer is the most common cause of cancer death worldwide and poses an immediate health threat. Despite decades of basic and clinical research, the 5-year survival rate for lung cancer patients is less than 10%.The most important drawbacks in efficient treatment of lung cancer are delayed diagnosis and absence of effective screening. Detection and study of precancerous lesions of the bronchial mucosa might be one of the turning points in understanding of neoplastic transformation. Therefore, it would be the most effective prevention and early treatment modality. We report a case of high-grade intraepithelial neoplasia of the bronchial mucosa in which a neoplastic growth in the lumen of intrinsic segment in the upper lobe of the left lung was detected on electronic bronchoscopy, and biopsy confirmed squamous papillary hyperplasia with high-grade intraepithelial neoplasia. CASE PRESENTATION: A 74-year-old male was admitted to the hospital due to a mass lesion in his left lung. After admission, computed tomography scan of the chest showed an intraluminal mass in the intrinsic segment of the upper lobe of the left lung and an enlarged left hilum. CONCLUSIONS: High-grade intraepithelial neoplasia of the bronchial mucosa is rare in the respiratory system. We report a case that can provide useful information for early diagnosis and treatment of the disease.