Fine needle aspiration cytology (FNAC) of salivary gland tumours: Repeat aspiration provides further information in cases with an unclear initial cytological diagnosis

Abstract 

Introduction

Fine needle aspiration cytology (FNAC) for salivary gland tumours requires expertise in interpretation. When a diagnosis is not clear (despite a cellular aspirate), published work is lacking on the value of repeating the test.

Methods

A retrospective study of 135 patients who had FNAC followed by definitive excision for a suspected salivary gland tumour. Accuracy was compared among those requiring repeat FNAC on one more occasion because of a non-diagnostic initial cytology report.

Results

33 patients (24% of study group) had repeat FNAC. A definite cytological diagnosis was subsequently made in 27/33 patients (82%). The sensitivity (84%) and specificity (93%) of repeat FNAC in distinguishing benign from malignant tumours was similar to initial FNAC (70% and 95%, respectively).

Conclusions

Repeat FNAC may provide a cytological diagnosis in cases where the initial diagnosis is not clear, although cytology should be used in conjunction with other investigations of salivary tumours, including image-guided biopsy examination where appropriate. Ideally salivary gland FNAC should be interpreted by a specialist pathologist.

Keywords: Salivary gland, Tumour, Fine needle aspiration cytology, Diagnosis, Head and neck