Prevalence and biological behaviour of variants of papillary thyroid carcinoma experience at a single institute

Abstract

There are many variants of papillary carcinoma, and some of these variants have been reported to show biological behaviours differing from that of conventional papillary carcinoma. In this study, we present our experience regarding the prevalence and prognoses of these variants of papillary carcinoma. H&E sections from 1521 patients who underwent initial surgery for papillary carcinoma in Kuma Hospital between 1987 and 1995 were re-reviewed and classified into conventional papillary carcinoma and various histological variants. We investigated the biological behaviours of these lesions, including prognoses. Follicular, tall cell and oncocytic variants were observed in comparably high incidences: 6.6%, 3.9%, and 1.9%, respectively. Patients with tall cell variant showed significantly worse disease-free survival (DFS) and cause-specific survival (CSS) rates than those with conventional papillary carcinoma. The prognoses of patients with follicular variant did not differ from those of patients with conventional papillary carcinoma. Patients with oncocytic variant have not shown carcinoma recurrence. Among the rare variants, which accounted for less than 1%, columnar cell carcinoma showed a worse prognosis. Since patients with some variants show different clinical outcomes from those with conventional papillary carcinoma, classification of variants might be helpful to predict patient prognosis.