Improving Adequacy of Fine-Needle Aspiration Cytology in Non-Thyroid Head and Neck Patients Using Concurrent Liquid...

Cytological evaluation of head and neck masses is an important diagnostic tool and aspect of pre-operative planning in Ear, Nose and Throat surgery. Samples acquired via fine-needle aspiration cytology (FNAC) may be processed as dry slides (conventional) or as liquid cytological preparation. Adequacy, defined as the quantity and quality of cellular material obtained, is a determinant of correct cytological diagnosis. This study aimed to investigate the adequacy of dry slide samples alone versus dry slides in combination with liquid cytological preparation in non-thyroid masses.

A single-centre study was undertaken between 2015 and 2018 at a District General Hospital Pathology unit. An initial retrospective analysis of adequacy data was undertaken over a nine month period from 1st January to 30th September 2015. All samples in this period were prepared as dry slides and obtained by two ENT surgeons and two radiologists. From 2017 onwards, samples were prepared as both dry slides and liquid cytology. Prospective re-audit of adequacy was undertaken over a nine month cycle in 2018. Individual clinicians' adequacy rates and overall adequacy were recorded in both cycles.

In the 2015 audit cycle, 134 of 207 (64.7%) samples were deemed adequate. In the 2018 re-audit, 156 of 202 (77.2%) samples were adequate. All four clinicians achieved higher adequacy rates in the re-audit cycle.

This study demonstrated promising improvement in overall and individual clinician adequacy rates following the introduction of liquid cytological preparation concurrently with dry slides. Collaborative research from further centres would increase sample size and allow higher validity.