Salivary gland tumors pose a diagnostic challenge to their diverse morphology and a vast range of biological behavior [1]. Pleomorphic adenoma (PA) is the most common salivary gland neoplasm. It is responsible for almost half of all neoplasms that arise in the head and neck area [2,3,7].

They more commonly arise from the major salivary glands, but may also originate from the minor salivary glands [2]. It is mostly situated in the parotid glands (85 %), followed by the minor salivary glands (10 %) and the submandibular glands (5 %). PA often presents as a slowly expanding tumor that can occur in people of any age, peaking between the ages of 30 and 50, with a small female predilection [2].

Willis gave it the name “pleomorphic adenoma” due to the histomorphological architectural variation (pleomorphism). It was previously known by other names such as a mixed tumor, enclavoma, branchioma, endothelioma, and enchondroma [5]. Consisting of both epithelial and myoepithelial cells, it is a benign mixed neoplasm. It is encapsulated in a fibrous capsule. One cell differentiates into either an epithelial or a myoepithelial cell, as opposed to malignant epithelial and myoepithelial cells multiplying simultaneously [4].

Histologically, PA displays a great diversity of morphologic features and growth patterns. Epithelial differentiation manifests as a mixture of well-formed duct-like structures closely related to myoepithelial cells, which exhibit diverse morphology including the spindled, rounded, angular, plasmacytoid, polygonal, and mucous appearance [2]. The stroma of these tumors may comprise myxoid, chondroid, myxoid, chondromyxoid, hyaline, fibrous, and sclero-hyaline. Very rarely, osseous and adipose metaplasia can be found [2].

PA exhibits a wide range of morphologic characteristics and growth patterns histologically. Myoepithelial cells, which have a variety of morphologies such as spindled, rounded, angular, plasmacytoid, polygonal, and mucous appearances, are closely related to well-formed duct-like structures that are the manifestation of epithelial differentiation [2]. These tumors' stroma may include chondroid, myxoid, chondromyxoid, hyaline, fibrous, and sclero-hyaline components. Adipose and osseous metaplasia are extremely uncommon [2].

Even though PA is benign, managing it clinically can occasionally be difficult due to its tendency towards recurrence and risk of malignant transformation, which can range from 2.8 % to 46.6 % and 3.3 % to 13 % of cases, respectively [2]. While focal necrosis, extensive hyalinization, vascular or capsule invasion, hypercellularity, and atypical mitosis seem to be associated with a higher risk of malignant transformation, some histopathological changes, such as stroma-rich variant and capsular infiltration, may be linked to an increased risk of recurrence of PA [6].

With an emphasis on the variety of their morphologic aspects, this study sought to conduct a retrospective analysis of the clinicopathological characteristics of salivary gland PAs diagnosed in a tertiary Indian hospital.