[Thyroid carcinoma--differentiated, poorly differentiated and anaplastic carcinoma]

Abstract

The poorly differentiated carcinoma was first added as a new member in the lists of classification of thyroid carcinomas in the WHO 2004 edition. However its histological criteria include necrosis and increased mitoses in addition to the original definition by Sakamoto's proposal, solid, trabecular and schirrhous growth. This modification creates a significant change in the incidence and prognosis of this carcinoma. This carcinoma, defined by the new WHO classification, is about 1-5% of all thyroid malignancy and has more aggressive outcome than the previous definition.