Papillary microcarcinoma

Pathological criteria for classifying thyroid cancer may show discrepancies in the differentiation between foUicu-lar adenoma and minimally invasive follicular carcinoma, and between follicular neoplasia and the folficular variant of papillary carcinoma (Lloyd et al., 2004 Saxen et ai, 1978). The inclusion of papillary microcarcinomas (1.0 cm or less in diameter), which are usually incidental findings or detected by the use of ultrasound-guided thyroid fine-needle aspiration cytology (Lin et al., 1997), the existence of radioactive fallout, which may lead to an increase of differentiated thyroid carcinoma and a rise in population age with time, should also be taken into account when analyzing the epidemiology of thyroid cancer. 

Despite few controversial studies reporting the detection of RET/PTC rearrangements in benign or non-papillaty thyroid lesions such as Hashimoto thyroiditis, follicular and Hiirthel cell adenoma, the RET rearrangements seems to be characteristic for papillary thyroid carcinoma and not reported in any other thyroid carcinoma. The reported positive results in other thyroid lesion are possibly due to the presence of microfocus of papillary microcarcinoma, latent carcinoma or atypical follicular cells in transformation. 

Endocrine Black discoloration of the thyroid gland occurred in a 31-year-old woman who had taken minocycline for 18 months before presenting with hyperthyroidism and a palpable thyroid nodule a concurrent papillary microcarcinoma was probably coincidental [135 ]. 

A rise in papillary carcinoma from most series is accompanied by a decrease in the incidence of follicular carcinoma, which was sometimes not as marked as in Salta (Tables 53.4 and 53.6), probably due to the use of routine systematic capsule sampling from follicular neoplasms from the 1980s leading to more frequent identification of minimally invasive follicular carcinomas (Harach et al, 2002 Harach and Williams, 1995 Lang et al, 1980). If this had occurred, the real change in the papillary to follicular carcinoma ratio would have been greater, but would not have affected the incidence of papillary carcinomas, as microcarcinomas were excluded. Furthermore, an increase... 

---