The Myriad Spectrum of Salivary Gland Lesions: Cytohistological Correlation on Fine Needle Aspiration Cytology, Core Needle Biopsy, and Resections in a 5-Year Single Institutional Experience of North India

Abstract

Introduction: Fine needle aspiration cytology (FNAC) is a cost-effective method used for preoperative diagnosis of salivary gland lesions. Due to the wide range of tumor types, overlapping morphology, and limited cellularity, diagnosing salivary gland lesions on FNAC can be challenging. A pattern-based approach focusing on cellular and architectural features possible on core needle biopsy (CNB) can help refine differential diagnoses.

Objectives: This study aimed to assess the concordance between FNAC and histological diagnoses obtained from CNB, as well as examine the risk of malignancy (ROM), and evaluate the agreement between histopathological assessments and diagnoses of these lesions in both CNB and resection specimens.

Materials and methods: A retrospective observational study was conducted in the Department of Oncopathology at a tertiary cancer center of North India over a period of 5 years. Cases wherein diagnosis offered on two modalities-FNAC and CNB were-available, were included.

Results: A total of 105 cases were identified. Category VI was the predominant category (60.95%) and the ROM in categories II, III, and IV was higher compared to that mentioned in the Milan System for Reporting Salivary Gland Cytopathology. Correlation between FNAC and CNB was achieved in 78.1% of cases, and between CNB and the final diagnosis on resection specimen was attained in 100% of cases.

Conclusion: The limitations of FNAC can be obviated by the utilization of CNB. Ancillary studies such as immunohistochemistry and/or cytogenetics wherever necessary can be smoothly applied on biopsy material, establishing the precise diagnosis and thereby providing definitive direction to further management.

Keywords: FNAC; core needle biopsy; cytology; histopathology; salivary gland.

FIGURE 1

Example of case with discordance with respect to Category I: (A) Inflammation‐rich smear with occasional scattered acinar cells, nondiagnostic on FNAC (×100, Papanicolaou stain); (B) corresponding histology revealed features of Kimura disease. (×200, hematoxylin & eosin stain). [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 2

Example of case with discordance with respect to Category II: (A) FNAC diagnosis of chronic sialadenitis comprising clusters of ductal epithelial cells with oncocytic change, impinged by chronic inflammatory cells (×200, Papanicolaou stain); (B) corresponding histology revealed features of follicular lymphoma (×200, hematoxylin and eosin stain). [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 3

Example of case with discordance with respect to Category III: (A) Paucicellular smear displaying singly scattered atypical ductal epithelial cells with nucleomegaly, conspicuous nucleoli and moderate amount of eosinophilic cytoplasm, diagnosed as atypia of undetermined significance (×200, hematoxylin and eosin stain); (B) corresponding histology on the other hand disclosed features of epithelial‐myoepithelial carcinoma (×200, hematoxylin and eosin stain). [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 4

Example of case with discordance with respect to Category IVA: (A) diagnosed as pleomorphic adenoma on FNAC (×400, hematoxylin and eosin stain); (B) corresponding histology on the other hand disclosed features of synovial sarcoma (×400, hematoxylin and eosin stain); (C) immunohistochemistry divulging the reactivity of the tumor cells for TLE1 (×400, hematoxylin and eosin stain). [Color figure can be viewed at wileyonlinelibrary.com]