Multicentricity in papillary thyroid carcinoma: analysis of predictive factors.

Objectives: Multicentricity has been cited as a rationale for total thyroidectomy in patients with papillary thyroid carcinoma (PTC) confined to one lobe. The purpose of this study was to examine the incidence of multicentricity of PTC in a cohort of 165 patients with PTC confined to one lobe and to examine clinical and pathologic features that may help predict for the presence of contralateral disease.

Design: Retrospective review.

Setting: Tertiary care hospital.

Method: A retrospective review of 165 patients with PTC confined to one lobe treated at the Toronto General Hospital from 1992 to 1997 was performed.

Main Outcome Measure: The predictive factors affecting the presence of multicentricity of PTC were analyzed.

Results: The incidence of PTC present in the contralateral lobe was 56.3%. We were unable to find any correlation of multicentricity with age, sex, tumour size, extrathyroidal spread, thyroiditis, or tall cell variant of PTC. There were trends toward higher incidence of contralateral disease in those patients with a prior history of irradiation and those with lymphatic metastases, but these trends did not reach statistical significance.

Conclusions: The incidence of contralateral disease in papillary thyroid cancer treated at the Toronto Hospital was 56.3%. There was a higher incidence of contralaterality in those patients with a previous history of irradiation and in those with lymphatogenous metastases, but this did not reach statistical significance.