Nuclear features in thyroid cytology: features helpful for a morphological diagnosis in routine practice

Abstract

This review article describes nuclear features of a range of thyroid lesions to enable confident diagnosis in a multidisciplinary thyroid cancer setting. It is hoped that this will serve as a handy aide-mémoire when faced with diagnosis of thyroid FNA (fine needle aspiration) cytology in day-to-day practice. The existing literature has been reviewed to give the reader an overview of the classification systems in thyroid cytology and various entities described therein. The lesions are broadly categorised as benign, malignant, and indeterminate. The comparison to ultrasound imaging classification is given, with a view to have a broader understanding of the clinico-radiological context. Photographs with descriptions in each category are included together with a detailed description of nuclear features, pitfalls, and challenges in diagnosis. This article is designed for practising and trainee cytopathologists as a useful tool for everyday practice.