Correlating the accuracy of fine needle aspiration cytology and Histopathology in diagnosis of parotid tumours at four major hospitals in Zambia.

Abstract

Fine Needle Aspiration Cytology (FNAC) is a cheap, simple, quick, minimally invasive technique that is widely used for preoperative diagnosis of parotid tumours because the parotid gland is not amenable to preoperative sample collection techniques for histopathologic assessment to guide parotid surgery. Twenty-five (25) participants were prospectively studied over a two-year period at four major hospitals in Zambia. FNAC was done using a 10cc syringe and 20-22G needles for sample collection in consented participants. Specimen staining was done with Papanicolaou stain. Histopathology was assessed with haematoxylin and eosin (H&E) stained sections. FNAC correlated with histopathology with a sensitivity of 100% and specificity of 66.7%; positive and negative predictive values of 95.7% and 100% respectively and a likelihood ratio of 3. All parotid tumours were neoplastic with 76% benign and 24% malignant tumours on histopathology. FNAC accurately diagnosed 68% benign and 20% malignant tumours but was not able to diagnose 12% of the samples. This study found that FNAC correlated with histopathology in the diagnosis of parotid tumours. FNAC is useful in the preoperative assessment of parotid tumours as it provides a preoperative diagnosis that influences management by either avoiding surgery (inflammatory lesion) and limiting the extent of surgery for benign and malignant parotid tumours.

Key words: Parotid tumours, Fine Needle Aspiration Cytology (FNAC)