Diagnostic utility of cell block in salivary gland neoplasm with fine needle aspiration cytology and its clinicopathological correlation

Introduction: Cell block [CB] technique employs the retrieval of small tissue fragments from a fine needle aspiration cytology specimen [FNAC] which are processed to form a paraffin block and viewed as histology sections. Aim of the study to compare the role of FNAC & CB in diagnosis of salivary gland neoplasm, in term of adequacy, cytomorphological details and diagnostic efficiency.
Material & Methods: Total 83 salivary gland cases were enrolled in the study and categorization done according to Milan System for reporting salivary gland cytopathology. Both FNAC smears and Cell block sections were prepared as standard protocol and examined.
Results & Discussion: Most common diagnosis was benign 52 cases (Category IVA; 62.7%) followed by malignancy 17 cases (Category VI; 20.5%) and non-diagnostic 4 cases (Category I; 4.82%). Only 1 (1.2%) case each was diagnosed as suspicious (Category V) and salivary gland neoplasm of uncertain malignant potential (Category IVB). 6 (7.24%) cases were diagnosed as non-neoplastic (Category II) and 2 (2.4%) as atypia of undetermined significance (Category III). Specificity and PPV of both the techniques (FNAC and Cell Block) were found to be 100%. Sensitivity, NPV and diagnostic accuracy of FNAC technique were found to be comparable to that of Cell block technique (63.6% vs72.7%, 86.7% vs 89.3%, 86.8%vs 91.7%). Cell block as a technique should be used in routine practice as it not only increases the diagnostic yield, but ancillary test and retrospective studies can also be done.