HISTOLOGICAL-EVALUATION OF THYROID CARCINOMAS - REPRODUCIBILITY OF THE WHO CLASSIFICATION

Aims and Background: Thyroid carcinomas display several pathologic features, show different behavior and necessitate different treatment; thus correct classification is mandatory. Methods: The kappa statistic was used as a measure of agreement in a panel of seven pathologists who reviewed 200 cases of thyroid tumors. Results: Overall agreement was 83% (k = 68). Good agreement was found for anaplastic (k = 0.85) and papillary carcinomas (k = 0.81); agreement for medullary carcinoma was acceptable (k = 0.80), suboptimal for other (k = 0.67), and poor for follicular carcinoma (k = 0.54). Conclusions: Central pathology review of thyroid carcinomas is recommended when clinical and epidemiologic trials are planned.