Spectrum of Sinonasal Lesions with Expression of p16 and Ki-67 in Premalignant Lesions and Squamous Cell Carcinomas

Abstract

Introduction: Sinonasal masses are heterogeneous group of non-neoplastic and neoplastic lesions originating from epithelial, mesenchymal, haematolymphoid and neuroendocrine cells. Exact categorization and aetiological evaluation by histopathological and additional immunohistochemical examination are essential for individualized treatment. Aim: To evaluate the clinico-epidemiological variables of sinonasal lesions and to determine the role of Human Papilloma Virus (HPV) infection along with its correlation with Ki-67 level in squamous cell carcinomas and precursor lesions. Materials and Methods: An observational and crosssectional study was performed in a tertiary care hospital, in the Department of Pathology in collaboration with the Department of Otorhinolaryngology over 18 months from January 2015 to June 2016 including 87 patients. Haematoxylin and Eosin (H&E) stained sections were examined and reported according to WHO category. During immunohistochemical study with Ki-67 and p16, squamous lesions were categorized as Inflammatory Polyp (IfP), Inverted Papilloma (IvP), Exophytic Papilloma (EP), Squamous Cell Carcinoma arising in pre-existing Inverted Papilloma (IvP with SCC), Squamous Cell Carcinoma (SCC) and Sinonasal Undifferentiated Carcinoma (SNUC). Results: Among 87 cases, 39(44.83%) non-neoplastic lesions, 21(24.14%) benign neoplastic lesions and 27(31.03%) malignant neoplastic lesions were found. Ki-67 Labelling Index gradually increased from IfP (3.82%) to SNUC (85%). Expression of p16 was highest (50%) in IvP with SCC group and SNUC group than 33.3% in IvP group and SCC group. Conclusion: Simultaneous evaluation of p16 expression and cell cycle proliferation marker (Ki-67) revealed significant difference. Thus, HPV plays a pivotal role in oncogenesis and malignant transformation in squamous sinonasal lesions.

Keywords

• Human Papilloma Virus
• Sinonasal mass
• Squamous lesions