Thyroid malignancy among patients with thyroid nodules in the United Arab Emirates: a five-year retrospective tertiary Centre analysis.

Objectives: Thyroid malignancy constitutes the sixth common cancer type in the United Arab Emirates (UAE). There are no epidemiological data outlining the prevalence of cancer in thyroid nodules, nor previous analysis of ultra-sonographic features correlating with thyroid malignancy in the UAE. This study aimed to estimate the prevalence of thyroid malignancy in patients with thyroid nodules and to describe the ultra-sonographic characteristics of thyroid nodules harbouring malignancy.

Methods: A retrospective electronic medical records review of all thyroid nodules in patients (aged 18 to 80 years) with normal thyroid-stimulating hormone (TSH) levels, who underwent ultrasound guided fine needle aspiration cytology (UG-FNA) at Sheikh Khalifa Medical City (SKMC) during 2011-2015.

Results: 436 patients with normal TSH underwent UG-FNA cytological examination of thyroid nodules ( n  = 555 nodules). The overall crude prevalence of thyroid cancer among patients was 10.1% (95% CI 7.5-13.3). The age-adjusted prevalence of thyroid cancer among UAE nationals, Arabs, Far East Asians, and Caucasians were 9.6% (3.6-15.6), 10.0% (6.2-13.8), 16.8% (4.5-29.0) and 16.3% (1.7-30.9), respectively. The crude prevalence was 14.5%(95% CI 6.2-22.8) in men, and 9.3%(95% CI 6.3-12.2) in women. The echogenicity features were significantly different between the cancerous and noncancerous nodules ( p  = 0.025). Cancerous nodules were relatively more hyper- and hypo-echoic, while noncancerous nodules were mostly complex.

Conclusion: We report a higher prevalence of thyroid malignancy among patients with thyroid nodules relative to that reported in other parts of the world. The rate of thyroid malignancy was higher in patients of Far-East Asian and Caucasian ethnic background.