Multicentricity in papillary thyroid carcinoma: Analysis of predictive factors

Objectives: Multicentricity has been cited as a rationale for total thyroid ectomy in patients with papillary thyroid carcinoma (PTC) confined to one l obe, The purpose of this study was to examine the incidence of multicentric ity 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 pre sence of contralateral disease. Design: Retrospective review. Setting: Tertiary care hospital. Method: A retrospective review of 165 patients with PTC confined to one lob e treated at the Toronto General Hospital from 1992 to 1997 was performed. Main Outcome Measure: The predictive factors affecting the presence of mult icentricity 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, thyroid itis, or tall cell variant of PTC. There were trends toward higher incidenc e of contralateral disease in those patients with a prior history of irradi ation and those with lymphatic metastases, but these trends did not reach s tatistical significance. Conclusions: The incidence of contralateral disease in papillary thyroid ca ncer treated at the Toronto Hospital was 56.3%. There was a higher incidenc e of contralaterality in those patients with a previous history of irradiat ion and in those with lymphatogenous metastases, but this did not reach sta tistical significance.