Biphasic cell patterns of salivary gland tumors in a tertiary care hospital

Abstract

Introduction: Salivary gland tumors are relatively uncommon neoplasms of the head and neck region. These tumors mainly involve major salivary glands. Around 90% of the salivary gland tumors occur in the parotid glands followed by sub-mandibular glands. Tumour in the sublingual glands are uncommon. Malignant tumors generally occur in smaller salivary glands. Some of the salivary gland tumors show complex architecture and morphologic overlap. Some tumors show dual luminal-abluminal cell differentiation. Detailed histomorphologic analysis is required for proper diagnosis of these tumors which is very important for proper treatment and outcome. Objective: To study the biphasic cell patterns in salivary gland tumors of complex architecture. Materials and Methods: This study was conducted for a period of 4 years from January 2010 to December 2014 on the surgically resected salivary gland tumor specimens in the pathology department of M.S Ramaiah hospital in Bangalore, Karnataka. Standard protocol was followed for surgical grossing of the salivary gland specimens sent to the pathology department. Paraffin sections of 5µm thickness were prepared and stained by haematoxylin and eosin (H & E) for histopathological study. For all retrospective cases, histopathology reports, slides and paraffin blocks were retrieved and additional sections were made. A total of 66 cases were studied. Results: Out of total 66 cases studied, benign salivary gland tumors were 38 cases (57%) and malignant tumors were 28 cases (43%). Salivary gland tumors were commonly seen between 40- 60 years. Female preponderance was seen in all tumors except warthin tumor. The most common benign tumor was pleomorphic adenoma and the common malignant tumor was mucoepidermoid carcinoma. Common site for these tumors was parotid gland with notable exception being adenoid cystic carcinoma, which showed predilection for the minor salivary glands. Most of the tumor studied showed dual cell differentiation with mo