In the fifth edition 2022 classification several changes have been introduced into the classification of thyroid neoplasia. These include replacement of the pathological term 'multinodular goitre' with the term 'thyroid follicular nodular disease' in recognition that many of the nodules are neoplastic. The term 'Hurthle cell' has been replaced by the term 'oncocytic'. In addition to poorly differentiated 'insular' carcinoma, a new class of thyroid neoplasia with intermediate risk between anaplastic and low grade carcinoma of follicular cell origin has been introduced. This group of tumours termed 'high grade differentiated thyroid carcinoma' represents a parallel group to poorly differentiated insular carcinoma and current thinking is that treatment paradigms for the two entities should be similar.