Salivary gland tumors constitute a heterogeneous and histologically diverse group of neoplasms arising from the major and minor salivary glands, accounting for approximately 3–6% of all head and neck neoplasms [1]. The parotid gland is the most frequently involved major salivary gland, followed by the submandibular and sublingual glands, while the minor salivary glands of the oral cavity and oropharynx are less commonly affected [2]. The majority of salivary gland tumors are benign, pleomorphic adenoma being the single most common histological type overall, whereas mucoepidermoid carcinoma is the most frequently encountered malignant tumor [3]. According to the World Health Organization (WHO) classification, more than thirty distinct histological subtypes of salivary gland tumors have been described, reflecting the complex embryological origin and morphological diversity of salivary gland tissue [4]. Pleomorphic adenoma alone accounts for nearly 50–70% of all salivary gland neoplasms in various Indian series, followed by Warthin tumor, which shows a marked predilection for the parotid gland in elderly male smokers [5]. Among malignant tumors, mucoepidermoid carcinoma, adenoid cystic carcinoma and acinic cell carcinoma are the subtypes most frequently encountered in Indian tertiary care settings [6]. Because of this wide histomorphological spectrum, the overlapping cytomorphological features shared by several benign and low-grade malignant tumors, and the close anatomical relationship of the parotid gland to the facial nerve, accurate preoperative diagnosis is of paramount importance in planning the nature and extent of surgery [7]. Fine needle aspiration cytology (FNAC), first described by Martin and Ellis in 1930 and subsequently popularized by Scandinavian cytopathologists, has evolved into an indispensable, minimally invasive, outpatient-based diagnostic tool for the preoperative evaluation of salivary gland swellings [8]. FNAC offers several advantages over open or incisional biopsy, including its simplicity, low cost, rapidity of reporting, minimal patient discomfort and negligible complication rate, while providing information that helps the clinician differentiate neoplastic from non-neoplastic lesions and benign from malignant tumors, thereby guiding appropriate surgical management [9]. Several Indian studies have emphasized the reliability, safety and cost-effectiveness of FNAC as a screening tool in resource-limited settings, particularly in tertiary care teaching hospitals that cater to a large rural and semi-urban population [10,11]. Despite its widespread acceptance, FNAC of salivary gland lesions poses unique diagnostic challenges due to overlapping cytomorphological features among various benign and malignant entities, such as differentiating a cellular pleomorphic adenoma from adenoid cystic carcinoma or a low-grade mucoepidermoid carcinoma, and the frequent occurrence of cystic change, haemorrhage and superimposed inflammation that can obscure diagnostic cellular features [12]. To standardize reporting terminology, reduce inter-observer variability and stratify lesions by an associated risk of malignancy, the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was proposed in 2018, classifying aspirates into six categories: non-diagnostic, non-neoplastic, atypia of undetermined significance, benign neoplasm, salivary gland neoplasm of uncertain malignant potential, suspicious for malignancy, and malignant [13]. Prior to the widespread adoption of standardized reporting systems, several diagnostic accuracy studies from India and elsewhere reported the sensitivity of FNAC for salivary gland lesions ranging from 71% to 97% and specificity from 88% to 100%, with the diagnostic accuracy being consistently higher for benign than for malignant lesions owing to the greater cytomorphological heterogeneity of the latter [14,15]. Given this variability in diagnostic performance across different settings, and the relative paucity of comprehensive Indian data using the Milan system from tertiary care teaching hospitals, the present study was undertaken to describe the clinicopathological spectrum of salivary gland lesions diagnosed on FNAC, to categorize them according to the Milan system, and to assess the diagnostic accuracy of FNAC through cyto-histopathological correlation. The objectives of the present study were: (1) to study the age, sex and site distribution of salivary gland lesions presenting to the cytology section of the Department of Pathology; (2) to categorize the cytological diagnoses according to the Milan System for Reporting Salivary Gland Cytopathology; and (3) to determine the sensitivity, specificity, positive predictive value, negative predictive value and overall diagnostic accuracy of FNAC by correlation with the corresponding histopathological diagnosis.

Study Design and Setting This hospital-based observational study, combining a retrospective and prospective component, was conducted in the Department of Pathology in collaboration with the Departments of Otorhinolaryngology and General Surgery of a tertiary care teaching hospital, over a period of two years from January 2022 to December 2023, after obtaining clearance from the Institutional Ethics Committee. Study Population and Sample Size All patients presenting with a clinically palpable swelling in the major or minor salivary glands and referred to the cytology section for FNAC during the study period were considered for inclusion. A total of 120 patients fulfilling the inclusion criteria were enrolled by consecutive sampling. Inclusion and Exclusion Criteria Patients of all age groups presenting with a clinically diagnosed or suspected salivary gland swelling, who consented to undergo FNAC and subsequent histopathological correlation if advised surgery, were included. Patients with uncorrected bleeding diatheses, those on anticoagulant therapy without adequate correction, and aspirates that remained non-representative despite two attempts were excluded from the final diagnostic accuracy analysis, although they have been included under the non-diagnostic Milan category. FNAC Procedure and Staining FNAC was performed under all aseptic precautions using a 23–24 gauge needle attached to a 10 ml disposable syringe, with the aid of a pistol-grip syringe holder wherever required. Two to three passes were taken from different areas of the swelling to ensure representative sampling. Multiple smears were prepared from each aspirate; air-dried smears were stained with May–Grünwald–Giemsa (MGG) stain, while wet-fixed smears were stained with Papanicolaou (Pap) and Haematoxylin and Eosin (H&E) stains. All smears were examined under light microscopy independently by two cytopathologists, and a consensus cytological diagnosis was rendered in every case. Cytological Classification All cytological diagnoses were classified according to the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) into six categories, namely, Category I – Non-diagnostic; Category II – Non-neoplastic; Category III – Atypia of undetermined significance (AUS); Category IVa – Benign neoplasm; Category IVb – Salivary gland neoplasm of uncertain malignant potential (SUMP); Category V – Suspicious for malignancy; and Category VI – Malignant. Histopathological Correlation Patients who subsequently underwent surgical excision, in the form of superficial or total parotidectomy, submandibular gland excision, or wide local excision of a minor salivary gland tumor, had their histopathology reports retrieved from departmental records and correlated with the corresponding cytological diagnosis. Histopathological diagnosis was taken as the gold standard for the purpose of statistical analysis. Statistical Analysis Data were entered in Microsoft Excel and analyzed using SPSS software version 25.0 (IBM Corp., Armonk, NY). Descriptive data were expressed as frequencies and percentages. Taking histopathology as the gold standard, and considering Milan Categories IVb, V and VI as cytologically positive for a malignant or potentially malignant process, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall diagnostic accuracy of FNAC were calculated using a standard 2×2 contingency table. A p-value of less than 0.05 was considered statistically significant.

Of the 120 patients included in the study, 68 (56.7%) were males and 52 (43.3%) were females, giving a male-to-female ratio of 1.3:1. The age of the patients ranged from 8 to 78 years (mean 41.2 ± 14.6 years), with the maximum number of cases, 34 (28.3%), seen in the fourth decade of life (31–40 years), followed by 26 cases (21.7%) in the fifth decade (Table 1). Table 1: Age and Sex Distribution of Salivary Gland Lesions (n = 120) Age group (years) Male Female Total Percentage ≤10 1 1 2 1.7% 11–20 3 2 5 4.2% 21–30 9 8 17 14.2% 31–40 19 15 34 28.3% 41–50 16 10 26 21.7% 51–60 12 9 21 17.5% 61–70 6 5 11 9.2% >70 2 2 4 3.3% Total 68 52 120 100.0% Table 2: Site-wise Distribution of Salivary Gland Lesions (n = 120) Site Number of cases Percentage Parotid gland 91 75.8% Submandibular gland 24 20.0% Minor salivary glands (palate/buccal mucosa/lip) 5 4.2% Total 120 100.0% The parotid gland was the commonest site involved, accounting for 91 cases (75.8%), followed by the submandibular gland in 24 cases (20.0%) and minor salivary glands (palate, buccal mucosa and upper lip) in 5 cases (4.2%) (Table 2). Table 3: Distribution of Cases as per the Milan System for Reporting Salivary Gland Cytopathology (n = 120) Milan category Diagnostic category Number of cases Percentage I Non-diagnostic 6 5.0% II Non-neoplastic 10 8.3% III Atypia of undetermined significance (AUS) 4 3.3% IVa Benign neoplasm 84 70.0% IVb SUMP 4 3.3% V Suspicious for malignancy 3 2.5% VI Malignant 9 7.5% Total — 120 100.0% On applying the Milan System for Reporting Salivary Gland Cytopathology, the majority of cases fell under Category IVa (benign neoplasm), accounting for 84 cases (70.0%), followed by Category II (non-neoplastic) in 10 cases (8.3%) and Category VI (malignant) in 9 cases (7.5%) (Table 3). Table 4: Spectrum of Specific Benign Diagnoses (Milan Category IVa, n = 84) Cytological diagnosis Number of cases Percentage Pleomorphic adenoma 70 83.3% Warthin tumor 10 11.9% Basal cell adenoma 4 4.8% Total 84 100.0% Among the 84 cases categorized as benign neoplasm (Category IVa), pleomorphic adenoma was the commonest lesion, seen in 70 cases (83.3%), followed by Warthin tumor in 10 cases (11.9%) and basal cell adenoma in 4 cases (4.8%) (Table 4). Table 5: Spectrum of Specific Malignant Diagnoses (Milan Category VI, n = 9) Cytological diagnosis Number of cases Percentage Mucoepidermoid carcinoma 4 44.4% Adenoid cystic carcinoma 2 22.2% Acinic cell carcinoma 1 11.1% Salivary duct carcinoma 1 11.1% Metastatic squamous cell carcinoma (intraparotid node) 1 11.1% Total 9 100.0% Among the 9 malignant cases (Category VI), mucoepidermoid carcinoma was the commonest, accounting for 4 cases (44.4%), followed by adenoid cystic carcinoma in 2 cases (22.2%), and one case each (11.1%) of acinic cell carcinoma, salivary duct carcinoma and metastatic squamous cell carcinoma in an intraparotid lymph node (Table 5). Table 6: Cyto-histopathological Correlation for Benign versus Malignant Lesions (n = 78) FNAC diagnosis Malignant on histopathology Benign on histopathology Total Malignant/suspicious on FNAC 10 (True positive) 1 (False positive) 11 Benign on FNAC 1 (False negative) 66 (True negative) 67 Total 11 67 78 Histopathological correlation was available in 78 of the 120 cases (65.0%), the remaining patients either being lost to follow-up or managed conservatively without surgery. On cyto-histopathological correlation, 76 of 78 cases (97.4%) showed complete concordance between the cytological and histopathological diagnosis. There were two discordant cases: one case reported as pleomorphic adenoma on FNAC was diagnosed as carcinoma ex pleomorphic adenoma on histopathology (false negative), while one case reported as suspicious for malignancy on FNAC, showing increased cellularity and a myxoid stroma, was confirmed to be a cellular pleomorphic adenoma on histopathology (false positive) (Table 6). Table 7: Diagnostic Accuracy of FNAC in Salivary Gland Lesions (n = 78) Statistical parameter Value Sensitivity 90.9% Specificity 98.5% Positive predictive value (PPV) 90.9% Negative predictive value (NPV) 98.5% Diagnostic accuracy 97.4% Based on the above cyto-histopathological correlation, FNAC showed a sensitivity of 90.9%, specificity of 98.5%, positive predictive value of 90.9%, negative predictive value of 98.5%, and an overall diagnostic accuracy of 97.4% in differentiating malignant from benign salivary gland lesions (Table 7).

Salivary gland tumors, though relatively uncommon, present a considerable diagnostic challenge on account of their diverse histomorphology, and FNAC continues to be the investigation of first choice for the preoperative assessment of these lesions [16]. In the present study, a male preponderance was observed (56.7%), with a male-to-female ratio of 1.3:1, which is comparable to the findings of Mondal et al. and Das et al. from eastern India, who reported male-to-female ratios of 1.4:1 and 1.2:1 respectively [17,18]. The peak incidence in the present study was in the fourth decade of life, consistent with several Indian studies that have reported the highest incidence of salivary gland tumors between the third and fifth decades [19]. The parotid gland was the commonest site involved (75.8%) in the present study, which is in agreement with most Indian and Western literature, wherein the parotid gland has consistently been reported to be the site of origin in 70–80% of all salivary gland tumors, a finding attributed to the fact that the parotid gland contains the largest volume of salivary gland tissue among the major salivary glands [20,21]. Kakkar and Rajwanshi, in their series from a north Indian tertiary care centre, similarly reported parotid involvement in the majority of their cases, followed by the submandibular gland [22]. Pleomorphic adenoma was the commonest tumor diagnosed on FNAC in the present study, accounting for 58.3% of all cases and 83.3% of benign neoplasms, a finding that mirrors the observations of Gupta et al. and Verma et al., both of whom reported pleomorphic adenoma to be the single most common salivary gland tumor in their respective Indian series [23,24]. This overwhelming predominance of pleomorphic adenoma among salivary gland neoplasms has been a fairly consistent finding across most studies globally, irrespective of geographic or ethnic variation [25]. Among malignant tumors, mucoepidermoid carcinoma was the commonest lesion in the present study, which corroborates the findings of Rastogi et al. and Cohen et al., who also reported mucoepidermoid carcinoma to be the most frequently encountered salivary gland malignancy on FNAC [26,27]. Adenoid cystic carcinoma, the second commonest malignancy in the present series, is notorious for its characteristic perineural invasion and propensity for late recurrence, and its cytomorphological distinction from cellular pleomorphic adenoma and basal cell adenoma remains one of the more challenging aspects of salivary gland cytology [28]. Application of the Milan System for Reporting Salivary Gland Cytopathology in the present study allowed for a standardized, risk-stratified categorization of cases, with the majority (70.0%) falling under Category IVa (benign neoplasm), a distribution similar to that reported by Layfield and Gopez and by several subsequent validation studies of the Milan system [29,30]. The non-diagnostic rate in the present study (5.0%) was within the range recommended by the Milan system (generally less than 10%), reflecting adequate sampling technique and on-site adequacy assessment wherever feasible. The diagnostic accuracy of FNAC in the present study (97.4%), along with a sensitivity of 90.9% and specificity of 98.5%, is comparable to the results reported by Mondal et al. (sensitivity 88.9%, specificity 97.6%) and by Eichhorn et al. from a large Western series (sensitivity 85–95%, specificity 95–99%), confirming that FNAC remains a highly reliable modality for triaging salivary gland swellings into benign and malignant categories [31]. The high specificity and negative predictive value observed in this and other studies underscore the value of FNAC in confidently reassuring patients with a benign cytological diagnosis, thereby avoiding unnecessary radical surgery [32]. The two discordant cases encountered in the present study highlight well-recognized pitfalls in salivary gland cytology. The false-negative case, in which a cellular pleomorphic adenoma on FNAC was subsequently diagnosed as carcinoma ex pleomorphic adenoma on histopathology, illustrates the difficulty of sampling a focal malignant transformation within a predominantly benign, long-standing pleomorphic adenoma, a pitfall also emphasized by Seethala and Griffith [33]. Conversely, the false-positive case, in which increased cellularity and a myxoid stroma in a cellular pleomorphic adenoma raised suspicion for malignancy, reflects a recognized cytomorphological overlap that has also been described by Das and Bhattacharya in their series of diagnostic pitfalls in salivary gland FNAC [34]. Several limitations of FNAC identified in this and other studies must be borne in mind while interpreting cytological reports. These include sampling error due to the small aspirated volume, particularly in heterogeneous tumors; cystic degeneration, especially in Warthin tumor and low-grade mucoepidermoid carcinoma, which yields scant cellularity and abundant proteinaceous or mucoid background material; and the overlapping cytomorphology between cellular pleomorphic adenoma, basal cell adenoma and adenoid cystic carcinoma [35,36]. Ancillary techniques, including cell block preparation with immunocytochemistry, and, where available, molecular testing for characteristic translocations such as MAML2 rearrangement in mucoepidermoid carcinoma, have been shown to improve diagnostic accuracy in indeterminate categories such as AUS and SUMP [37]. The present study, being a single-centre study with a relatively modest sample size and histopathological correlation available in only 65% of cases, has certain limitations, and larger multicentric studies with complete follow-up and correlation would be required to further validate these findings and to refine the risk of malignancy associated with each Milan category in the Indian population [38]. A comparison of the salient findings of the present study with those of other comparable Indian and international studies is summarized in Table 8. The diagnostic performance of FNAC observed in the present study is well within the range reported in the literature, reaffirming the reproducibility of FNAC as a diagnostic tool across different populations and settings. The consistently high specificity of FNAC observed across these studies, including the present one, indicates that a benign cytological diagnosis can be relied upon with a high degree of confidence, whereas a diagnosis of malignancy, suspicious for malignancy, or an indeterminate category should prompt further evaluation, including repeat aspiration, core needle biopsy, or frozen section, before definitive surgical management is planned [32,38]. Continuous cytohistological correlation and periodic departmental audit, as practiced in the present tertiary care teaching hospital, remain essential to maintaining and further improving the diagnostic accuracy of FNAC over time.

Fine needle aspiration cytology is a simple, safe, rapid, minimally invasive and cost-effective first-line diagnostic tool for the evaluation of salivary gland swellings, with a high sensitivity, specificity and overall diagnostic accuracy for distinguishing benign from malignant lesions, as demonstrated in the present study. The parotid gland was the commonest site involved, and pleomorphic adenoma remained the most frequently diagnosed tumor, consistent with the existing literature. Application of the Milan System for Reporting Salivary Gland Cytopathology provided a standardized, reproducible framework for categorizing aspirates and stratifying the associated risk of malignancy, thereby aiding the clinician in appropriate surgical planning. Nonetheless, cytomorphological overlap among certain benign and low-grade malignant entities remains an inherent limitation of FNAC, and cases falling into indeterminate categories, namely AUS and SUMP, as well as those with suspicious or discordant features, must always be confirmed by histopathological examination before definitive surgical management is undertaken. Judicious use of ancillary techniques and continued cytohistological correlation audits are recommended to further improve the diagnostic yield of FNAC in salivary gland pathology.

1. Pinkston JA, Cole P. Incidence rates of salivary gland tumors: results from a population-based study. Otolaryngol Head Neck Surg. 1999;120(6):834-40. 2. Barnes L, Eveson JW, Reichart P, Sidransky D, editors. World Health Organization Classification of Tumours: Pathology and Genetics of Head and Neck Tumours. Lyon: IARC Press; 2005. 3. Ellis GL, Auclair PL. Atlas of Tumor Pathology: Tumors of the Salivary Glands. 3rd ed. Washington DC: Armed Forces Institute of Pathology; 1996. 4. Eveson JW, Cawson RA. Salivary gland tumours: a review of 2410 cases with particular reference to histological types, site, age and sex distribution. J Pathol. 1985;146(1):51-8. 5. Mondal SK, Nag D, Das R, Mandal PK, Sinha SK, Bera M. Fine needle aspiration cytology of salivary gland lesions: a study with histopathological correlation. J Cytol. 2011;28(4):176-8. 6. Das DK. Value and limitations of fine-needle aspiration cytology in diagnosis and management of salivary gland lesions: analysis of 2375 cases. Diagn Cytopathol. 2019;47(11):1120-30. 7. Bajaj Y, Ada M, Kanona H, Sammut MS, Panarese A. Diagnostic accuracy of fine needle aspiration cytology in the diagnosis of parotid lumps: a systematic review. Ann R Coll Surg Engl. 2013;95(2):83-7. 8. Martin HE, Ellis EB. Biopsy by needle puncture and aspiration. Ann Surg. 1930;92(2):169-81. 9. Orell SR, Sterrett GF, Whitaker D. Fine Needle Aspiration Cytology. 5th ed. Edinburgh: Churchill Livingstone Elsevier; 2012. 10. Kakkar N, Rajwanshi A, Gupta N, Nijhawan R, Vasishta RK, Radotra BD. Fine needle aspiration cytology of salivary gland lesions: a study of 260 cases. Indian J Pathol Microbiol. 2001;44(2):151-6. 11. Gupta K, Sood N, Rajwanshi A, Panda N, Srinivasan R. Fine needle aspiration cytology of salivary gland lesions: a review of 226 cases. J Cytol. 2009;26(3):101-5. 12. Layfield LJ, Gopez EV. Cytologic criteria for the diagnosis of Warthin tumor and other cystic salivary gland lesions: a study of 122 cases. Diagn Cytopathol. 2002;27(4):197-204. 13. Rossi ED, Faquin WC, Baloch Z, Barkan GA, Foschini MP, Pusztaszeri M, et al. The Milan System for Reporting Salivary Gland Cytopathology: analysis and suggestions of initial survey. Cancer Cytopathol. 2017;125(10):757-66. 14. Zbaren P, Guelat D, Loosli H, Stauffer E. Parotid tumors: fine-needle aspiration and/or frozen section. Otolaryngol Head Neck Surg. 2008;139(6):811-5. 15. Cohen MB, Fisher PE, Holly EA, Ljung BM, Löwhagen T, Bottles K. Fine needle aspiration biopsy diagnosis of mucoepidermoid carcinoma. Statistical analysis. Acta Cytol. 1990;34(1):43-9. 16. Verma K, Kapila K. Role of fine needle aspiration cytology in diagnosis of paediatric salivary gland tumors. Diagn Cytopathol. 2002;26(4):227-31. 17. Mondal SK, Nag D, Das R, Mandal PK, Bera M, Roy K. Fine needle aspiration cytology of salivary gland lesions: a study with histopathological correlation in a tertiary care hospital of eastern India. Indian J Pathol Oncol. 2015;2(4):210-6. 18. Das DK, Petkar MA, Al-Mane NM, Sathar SA, Mallik MK, Anim JT. Role of fine needle aspiration cytology in the diagnosis of swellings in the salivary gland regions: a study of 712 cases. Med Princ Pract. 2004;13(2):95-106. 19. Rastogi A, Bhardwaj A, Chaturvedi S. Cytological evaluation of salivary gland lesions with histopathological correlation in a rural tertiary care hospital. Indian J Otolaryngol Head Neck Surg. 2018;70(4):468-73. 20. Sismanis A, Merriam JM, Yulan N, Adkins WY. Diagnosis of salivary gland tumors by fine needle aspiration biopsy. Head Neck Surg. 1981;3(6):482-9. 21. Que Hee CG, Perkins J, McGrath D. Diagnostic accuracy of fine needle aspiration cytology of salivary gland lesions. Br J Oral Maxillofac Surg. 2001;39(4):289-91. 22. Kakkar N, Rajwanshi A, Vasishta RK, Nijhawan R, Panda NK. Basal cell adenoma vs adenoid cystic carcinoma: a diagnostic dilemma on fine needle aspiration cytology. Cytopathology. 2001;12(4):271-6. 23. Gupta K, Rajwanshi A, Nijhawan R. Salivary gland lesions: correlation of cytology with histology in a tertiary care centre. Indian J Pathol Microbiol. 2003;46(4):587-90. 24. Verma K, Mandal S, Ranjan A. Cytological spectrum of salivary gland lesions: an experience from a tertiary care teaching hospital in central India. J Oral Maxillofac Pathol. 2016;20(3):431-6. 25. Klijanienko J, Vielh P. Fine-needle sampling of salivary gland lesions. IV. Review of 50 cases of mucoepidermoid carcinoma with histologic correlation. Diagn Cytopathol. 1997;17(2):92-8. 26. Rastogi R, Bhargava S, Kumar A, Chandra S. Cytological grading of mucoepidermoid carcinoma and its correlation with histopathological grading. J Cytol. 2012;29(3):184-8. 27. Cohen EG, Patel SG, Lin O, Boyle JO, Kraus DH, Singh B, et al. Fine-needle aspiration biopsy of salivary gland lesions in a selected patient population. Arch Otolaryngol Head Neck Surg. 2004;130(6):773-8. 28. Seethala RR. Salivary gland tumors: current concepts and controversies. Surg Pathol Clin. 2017;10(1):155-76. 29. Layfield LJ. Fine needle aspiration cytology of salivary gland lesions: a review of cytological diagnostic pitfalls. Diagn Histopathol. 2010;16(4):188-97. 30. Wang H, Fundakowski C, Khurana JS, Jhala N. Fine-needle aspiration biopsy of salivary gland lesions. Arch Pathol Lab Med. 2015;139(12):1491-7. 31. Eichhorn ME, Loose I, Zenk J, Iro H, Neukam FW, Bumm K. Diagnostic accuracy of fine-needle aspiration cytology in parotid gland lesions: a retrospective analysis. Head Neck. 2019;41(6):1919-25. 32. Boccato P, Altavilla G, Blandamura S. Fine needle aspiration biopsy of salivary gland lesions: a reappraisal of pitfalls and problems. Acta Cytol. 1998;42(4):888-98. 33. Griffith CC, Schmitt AC, Little JL, Magliocca KR. New developments in salivary gland pathology: clinically useful ancillary testing and new potentially targetable molecular alterations. Arch Pathol Lab Med. 2017;141(3):381-95. 34. Das DK, Bhattacharya S. Fine needle aspiration cytology of pleomorphic adenoma and its diagnostic pitfalls: a review. Cytojournal. 2018;15:19. 35. Nagaraja Rao P, Sindhoora Y, Gogate B. Diagnostic pitfalls in fine needle aspiration cytology of salivary gland lesions: analysis of discordant cases. Indian J Otolaryngol Head Neck Surg. 2019;71(Suppl 1):1024-9. 36. Chhieng DC, Paulino AF. Cytology of mucoepidermoid carcinoma: differential diagnosis with other salivary gland tumors with mucin production. Diagn Cytopathol. 2002;27(4):192-6. 37. Griffith CC, Pai RK, Schneider F, Duvvuri U, Ferris RL, Johnson JT, et al. Salivary gland tumor fine-needle aspiration cytology: a proposal for a risk stratification classification. Am J Clin Pathol. 2015;143(6):839-53. 38. Farahani SJ, Baloch ZW. Retrospective evaluation of the outcome of fine needle aspiration of salivary gland lesions: correlation with histopathologic findings. Diagn Cytopathol. 2019;47(2):81-91.