Role of FNAC in the Preoperative Diagnosis of Salivary Gland Lesions.

Abstract

The characteristic cytologic features of the common salivary gland lesions have been well-delineated in literature. However, there also exist cytologic pitfalls and overlapping features that make an accurate diagnosis difficult in few cases. The present study was designed to compare the cytologic findings of salivary gland lesions with the histologic diagnoses, in order to assess the sensitivity, specificity and diagnostic accuracy of FNAC, with an emphasis on discordant cases. Patients with suspected salivary gland enlargements, who were referred for FNAC, were included in this study, which was done over a 3 year period in a medical college hospital. FNAC was performed by using the standard procedure. Smears were stained by using Papanicolaou's and MGG stains. Cytologic diagnosis was compared with histopathologic diagnosis wherever it was available. Eighty eight patients with salivary gland swellings were included in the study. The ages of the patients ranged from 15 to 82 years, with the M:F ratio being 1.6:1. Out of 88 cases, 68 had swellings in parotid gland, 19 had them in submandibular gland and one had them in hard palate. Pleomorphic adenoma was the commonest neoplasm which was seen in our study. Mucoepidermoid carcinoma (MEC) was the only malignant lesion seen in our study. One each of Warthin's tumour (WT) and MEC were overdiagnosed and underdiagnosed respectively, the reason being squamous metaplasia in WT and subtle nature of malignant cells in low-grade MEC. WT and MEC can pose problems in cytologicdiagnosis. Sampling errors and interpretational errors can lead todiscordant diagnoses.