Evaluation of papillary thryoid carcinoma and its variants: multifocality in thyroid lobectomy and completion thyroidectomy - a single tertiary center retrospective study.

Aims: The American Thyroid Association (ATA) updated guidelines for the treatment of thyroid cancer, leading to a less aggressive approach depending on clinical-pathological features. As a result, the possibility to perform lobectomy versus total thyroidectomy has significantly increased. The majority of thyroid cancers are indolent with an excellent prognosis, while only 15% of patients with well-differentiated carcinoma, including papillary thyroid carcinoma (PTC), have locally advanced thyroid cancer (LATC) at diagnosis. We reviewed our practice in treating thyroid carcinoma over the last decade.

Methods: From January 2010 to December 2020, 1057 patients with uninodular benign and malignant thyroid lesions were reviewed.

Results: Among these cases, 77% were women with a median age of 49.3 years. The series involved 307 malignant diagnoses (29.05%) including 196 (61.6%) classic PTC and 38 (12%) aggressive variants of PTC, mostly tall cell variant (30 cases, 9.4%). Among malignant cases, multifocality was microscopically documented in 84 cases (26.4%). Using the ATA distribution of risk, there were 239 cases in the low risk and 68 in the intermediate risk categories. Second surgery was assessed in a total of 150 cases, showing 42 cases with additional thyroid cancer foci in the other lobe (26 single vs 16 multiple foci). Ten cases had metastatic perithyroidal lymph nodes.

Conclusion: Our data could be the basis for performing a longitudinal study in order to establish which risk factors can predict bilateral involvement and to suggest a tailored surgical approach.