Endocrine Abstracts

The recently (2015) revised American Thyroid Association guidelines for the management of differentiated thyroid cancer recognise the importance of histological subtype in risk stratification. The prevalence of thyroid cancer subtypes in an Irish population is unknown. We reviewed all histology reports of thyroid carcinoma from a quaternary referral centre over a 10 year period, 2005 to 2015. 675 reports were reviewed. Of these, 87% were reported as papillary thyroid cancer (PTC), 7% follicular, 2.5% medullary, 2.5% anaplastic, 1% mixed. Absolute case numbers of thyroid carcinoma reports increased from 32 in 2005 to 111 in 2014. We then examined the annual incidence of each histological subtype (follicular variant, papillary, mixed, tall cell, insular and diffuse sclerosing) of PTC. Follicular variant PTC increased from 7/23 (30%) in 2006 to 36/90 (40%) in 2014, while other variants remained unchanged. The histological subtypes associated with higher risk, tall cell, insular and diffuse sclerosing variants all remained uncommon (<5%). The apparent increase in follicular variant PTC might reflect a change in reporting methods but also raises the possibility of a changing disease pattern over time. Re-analysis of the original histology specimens is required to answer this question. This data examination is the first review of characteristics of thyroid cancer in an Irish population. It can be used in informing future planning of services and ensure that treatment outcomes are as good as internationally predicted outcomes based on initial risk stratification.