Clinical features of multifocal papillary thyroid carcinoma and risk factors of cervical metastatic lymph nodes

Objective: To analyze the clinical features of multifocal papillary thyroid carcinoma (PTC) and the risk factors of cervical metastatic lymph nodes.

Methods: A total of 1524 patients with papillary thyroid carcinoma admitted in Gansu Provincial Cancer Hospital from January 2020 to August 2021 were enrolled, including 492 cases of multifocal PTC and 1032 cases of unifocal PTC. The clinicopathologic features of multifocal PTC and unifocal PTC were analyzed by comparing their differences in gender, ethnicity, age, body mass index, accompanying diabetes mellitus, accompanying hypertension, preoperative thyroid stimulating hormone and thyroglobulin levels, location of lesions, maximum diameter of lesions, sum of lesion diameters, central metastatic lymph nodes, lateral cervical metastatic lymph nodes, presence of Hashimoto's thyroiditis, and thyroid capsule invasion. Patients were also assessed according to the presence or absence of central metastatic lymph nodes and lateral cervical metastatic lymph nodes to understand clinicopathological parameter differences, and multivariate logistic regression analysis was used to explore the risk factors.

Results: Compared with unifocal PTC group, multifocal PTC group had significantly higher proportion of patients aged over 55 years, accompanying hypertension, central metastatic lymph nodes or cervical metastatic lymph nodes, Hashimoto's thyroiditis and capsule invasion (all P<0.05); 55.1% of patients with multifocal PTC had lesions distributed bilaterally, and the maximum diameter and diameter sum of the lesions were greater than those in unifocal PTC group (all P<0.01). Multivariate logistic regression analysis showed that male, maximum diameter of lesion more than 7 mm, capsular invasion were independent risk factors for central metastatic lymph nodes (all P<0.05); while male, maximum diameter of lesion more than 7 mm, preoperative thyroglobulin more than 55 ng/mL, and central metastatic lymph nodes were risk factors for lateral cervical metastatic lymph nodes in patients with multifocal PTC (all P<0.05).

Conclusion: Patients with multifocal PTC have significantly higher central and lateral cervical metastatic lymph nodes, particularly for male patients with a maximum diameter of lesion more than 7 mm, invasion of capsule, and preoperative thyroglobulin more than 55 ng/mL.