Analysis of Various Histopathological Patterns in Pleomorphic Adenoma - An Institutional Case Study

ABSTRACT

Introduction: Pleomorphic adenoma, the most common benign mixed salivary gland tumor which accounts for 70-80%, is a biphasic tumor with dual origin from epithelial and myoepithelial elements. It shows a malignant transformation rate of 6%. Microscopically, pleomorphic adenoma characteristically displays vast morphologic diversity. This present study is done to analyze prevalence rates and histomorphological variations to better elucidate the pattern of occurrence, diagnosis and treat- ment plan of pleomorphic adenoma. Materials and Methods: This are a retrospective study which was conducted in a private institution, Chennai. Based on the proportion of parenchymal and stromal tumor components, the cases were classified into four subtypes as proposed by Foote and Frazell. Morphological patterns, cellular patterns, capsular alterations and Stromal components were analyzed and statisti- cally evaluated. Results: Our analysis showed an overall 0.87% of pleomorphic adenoma cases being reported were associated with minor salivary glands followed buccal mucosa and palate. All the reported cases showed Type II pattern with histological cellular pat- tern of spindle cells and ductal morphological pattern. Conclusion: We observed the great diversity of morphological aspects of the stroma in pleomorphic adenoma, in which many cases showed variation in morphology and cellularity associated with tumor location.