Papillary Thyroid Microcarcinoma - Do Classical Staging Systems Need to Be Changed?

It has been broadly demonstrated that there has been a dramatic, worldwide, increase in the incidence of papillary thyroid carcinoma (PTC). Leenhardt et al. [2004] showed that there was approximately a 10-fold increase in the ratio of thyroid cancer for the cohort born in 1978 compared to those born in 1928. Davies & Welch [2006] found that the incidence of thyroid cancer in the United States had more than doubled from 1973 to 2002 and that this augmentation was virtually entirely due to an increase in PTC. However, it is uncertain whether this increase is a real phenomenon, or whether it is simply due to an increased rate of detection. Practices for management of thyroid diseases were deeply modified over the past few decades. The wide availability of ultrasonography (US) and fine needle aspiration biopsy (FNAB), as well as the improved accuracy of histopathological examination of surgical samples (that is the thinness of the anatomical slice of the thyroid specimen) are indicated as causes of this so-called spreading of the epidemic [Grodski & Delbridge, 2008]. Furthermore, the characteristics of PTCs, especially its size at diagnosis, have changed over time.