Ultrasound-guided fine needle aspiration cytology and ultrasound examination of thyroid nodules in the UAE: A comparison.

BACKGROUND: Thyroid nodules are a common clinical finding and most are benign, however, 5-15% can be malignant. There is limited regional data describing the accuracy of ultrasound-guided fine needle aspiration (FNA) cytological examination compared to ultrasound examination of thyroid in patients who have undergone thyroid surgery. METHODS: A retrospective analysis of ultrasonographic (US) reports, FNA cytology reports and histopathology reports of 161 thyroid nodules presented at the endocrine center at Tawam hospital in Al Ain city, the United Arab Emirates during the period 2011-2019 was performed. US reports and images with FNA cytopathology reports and slides were reviewed by an independent radiologist and pathologist. RESULTS: In total, 40 nodules were reported as benign by US examination, while very low suspicious, low suspicious, intermediate suspicious and highly suspicious categories were reported in 21, 41, 14 and 45 nodules respectively. In addition, 68 nodules were reported as benign (Bethesda category II), while atypical follicular cells of unknown significance (Bethesda category III), follicular neoplasm (Bethesda category IV), suspicious for malignancy (Bethesda category V), and malignant (Bethesda category VI) categories were reported in 33, 9, 24 and 27 nodules respectively. The risk of malignancy for US benign nodules was 5%, while the risks of malignancy in very low suspicious, low suspicious, intermediate suspicious and highly suspicious nodules were 52%, 36%, 100% and 87%, respectively. The risk of malignancy for Bethesda category II was 3%, while the risks of malignancy in category III, IV, V and VI were 58%, 67%, 96% and 100%, respectively. CONCLUSION: Thyroid FNA cytological examination and ultrasonography are key tools in predicting malignancy in thyroid nodules. Thyroid nodules with the diagnosis of Bethesda category III & IV run a high risk of malignancy thus more vigilance is required.

BRAF and KRAS mutations in papillary thyroid carcinoma in the United Arab Emirates.

BACKGROUND: Papillary thyroid carcinoma (PTC) is the most common malignant thyroid neoplasm comprising 80-90% of all thyroid malignancies. Molecular changes in thyroid follicular cells are likely associated with the development of PTC. Mutations in serine/threonine-protein kinase (BRAF) and Rat sarcoma viral oncogene homolog (RAS) are commonly seen in PTC. METHODS: In total, 90 cases of PTC are randomly selected from archive paraffin blocks and 10µm sections were cut and processed for DNA extraction. BRAF V600E mutation and 8 types of KRAS mutations were investigated using Real Time PCR. RESULTS: BRAF V600E mutation was identified in 46% of PTC while KRAS mutations were seen in 11% of PTC. There was significant correlation between BRAF V600E mutation and PTC larger than 5cm in diameter, positive surgical margin and lymph node metastasis. BRAF V600E mutation was significantly higher in patients with less than 55-year of age than those more than 55-year of age. BRAF V600E mutation was significantly higher in patients with family history of thyroid cancer than those without. There was no significant difference in BRAFV600E mutation between males and females, PTC classic and follicular variants, unifocal and multifocal PTC. There was a significant higher percentage of BRAF V600E mutation in classic PTC than papillary microcarcinoma variant. There was no significant age, gender, histologic type, tumor size, lymph node metastasis, tumor focality, and surgical margin status differences between KRAS mutated and non-mutated PTC. CONCLUSION: BRAF V600E and KRAS mutation are seen in a significant number of PTC in the UAE. BRAF mutation is significantly correlated with large tumor size, positive surgical margins and lymph node metastasis suggesting an association between BRAF V600E mutation and tumor growth and spread.