Fine-needle aspiration cytology of salivary gland lesions

Abstract

Background: Fine-needle aspiration cytology (FNAC) is a sensitive, specific, cost-effective tool and has been widely used as a diagnostic tool for the management of various head-and-neck lesions. Salivary gland lesions constitute the most common head-and-neck lesions. These lesions can range from inflammatory to neoplastic, which can be either benign or malignant.

Materials and methods: The study was performed on 104 patients who presented with salivary gland swelling to the department of pathology at a tertiary care center from January 2016 to June 2020. FNAC was performed using a 22-24G needle, and smears were stained with Giemsa, hematoxylin and eosin and Papanicolaou stain. Histopathology was assessed on routine hematoxylin- and eosin-stained paraffin sections. The cytological and histopathological slides were studied, analyzed and correlated. Sensitivity, specificity, positive predictive value and negative predictive were calculated.

Results: The study included 104 cases in the age range of 10-70 years and a mean of 45 years (±16 standard deviation). There was a male preponderance with a male-to-female ratio of 1.6:1. The parotid gland was the most common site 91 (87%). On cytology, 71 (68%) were neoplastic, of which 58 (81%) were benign and 13 (19%) were malignant. Histopathological correlation was available in 36 cases (50%), 24 (67%) of which were benign and the remaining 12 (33%) were malignant. The sensitivity, specificity, positive predictive value and negative predictive value of the present study are 95%, 85%, 91% and 92%, respectively.

Conclusion: FNAC of the salivary gland is a safe, reliable and cost-effective technique which can be used as the first line of investigation in evaluating salivary gland lesions.

Keywords: Fine-needle aspiration cytology; salivary gland lesions; sensitivity; specificity.

Figure 1

Cytomorphology of sialadenosis showing benign salivary acini with few ductal cells (H&E, ×100)

Figure 2

(a) Cytomorphology of pleomorphic adenoma showing epithelial cells admixed with ovoid myoepithelial cells and chondromyxoid stroma (H&E, ×100); (b) Histomorphology of pleomorphic adenoma showing admixture of epithelial, myoepithelial and chondromyxoid stroma (H&E, ×100)

Figure 3

(a) Cytomorphology of Warthin's tumor showing sheets of oncocytic cells, polymorphous population of lymphocytes in a dirty granular background (H&E, ×40). Inset: Sheets of oncocytes with background of lymphocytes (H&E, ×400). (b) Histomorphology of Warthin's tumor showing cystic spaces lined by bilayered epithelium with lymphoid stroma (H&E, ×100)

Figure 4

(a) Cytomorphology of mucoepidermoid carcinoma showing cohesive clusters of intermediate cells in a background of foamy macrophages, mucus and debris (H&E, ×100). (b) Histomorphology of mucoepidermoid carcinoma showing cystic and solid areas. Cysts are lined by mucus-secreting columnar epithelium and solid areas showing intermediate squamous cells (H&E, ×100)

Figure 5

(a) The cytomorphology of adenoid cystic carcinoma showing small uniform epithelial cells with hyperchromatic nuclei and coarse chromatin adhering to a large, hyaline stromal globule (H&E, ×100). Inset: Tumor cells attached to hyaline globule (H&E, ×400); (b) Histomorphology of adenoid cystic carcinoma showing tumor cells arranged in cribriform pattern (H&E, ×100)

Figure 6

(a) Smears showing oncocytic cells in clusters, plenty of vacuolated macrophages and scattered lymphocytes (H&E, ×100); (b) Sections of secretory carcinoma showing lobular neoplasm with neoplastic cells arranged in papillary, microcystic pattern (H&E, ×400); (c) Neoplasm showing predominantly microcystic pattern with secretion within (H&E, ×400); (d) Immunohistochemical stain showing cytoplasmic positivity for mammaglobin. Inset: DOG-1: negative (×400)