Endocrine Abstracts

Background: PTMCs are papillary thyroid carcinoma nodules measuring ≤1cm. While the American Thyroid Association (ATA) do not recommend biopsy or follow-up for PTMC nodules, classifying it as a benign condition, some individuals develop cervical lymph node metastases (LNM), challenging its benign classification.

Methods: We identified 52 cases of PTMC among 2,000 thyroid patients from 156 MDT meetings at Cork University Hospital (CUH) between January 2013 and December 2018, and January 2022 to May 2022. Conducting retrospective database review, we stratified patients by presence or absence of LNM, analysing factors associated with metastases using crude tests of association and logistic regression.

Results: Of the 52 patients, 16 (31%) exhibited metastases; 1 (2%) patient exhibited sclerosing metastasis to adipose and skeletal muscle tissue. Another patient exhibited infiltrative growth patterns, while a third demonstrated extra-nodal lymphovascular invasion. 9 (17%) patients with LNM were identified pre-operatively. 7 (13%) patients had incidental PTMC discovery with LNM during surgery for benign conditions. The sizes of metastases ranged from 4mm to 28mm, and the number of positive nodes ranged from 1 to 15. Preliminary crude tests of correlation demonstrated that, nodules ≥5mm, extrathyroidal extension, and patient age ≤45 years correlated significantly with metastases (P = 0.004, P = 0.007, P = 0.01 respectively). When adjusting for confounding variables through regression analysis, these associations persisted. Furthermore, following this adjustment, a significant association between male gender and metastases was unveiled (OR 7.355, 95% CI 1.354-39.960, P = 0.021).

Conclusion: PTMC is a condition possessing malignant potential. Nodules ≥5mm, with extrathyroidal extension in male patients ≤45 years, are more likely to metastasise. Follow-up should be considered for such cases.