The aim of the present study was to present data on frequency of thyroid cancer in Mures County (Romania) and border counties, a goiter endemic area, and to analyze its histopathological characteristics, over a 20 years period (1990-2009).
Materials and methods: Demographic, clinical and pathological data were obtained from database registries. Histological subtypes of thyroid cancer were classified according to the WHO criteria (sixth edition, 2004) in the following categories: papillary thyroid carcinoma with its histological subtypes, follicular thyroid carcinoma, poorly differentiated thyroid carcinoma, undifferentiated thyroid carcinoma, medullary carcinoma, lymphoma, metastatic tumors.
Results: Our analyze included 524 cases of thyroid cancer of the 3460 surgical thyroid specimens resected between 1990-2009: 410 (78.2%) cases of papillary carcinoma, 19 (3.6%) cases of follicular carcinoma, 24 (4.6%) cases of poorly differentiated carcinoma, 33 (6.3%) cases of undifferentiated carcinoma, 22 (4.1%) medullary carcinomas, eight (1.6%) lymphomas, and eight (1.6%) metastatic tumors. Papillary thyroid carcinoma is the most common histological form (78%) and an increasing incidence of this form was observed. A statistical significant increase in the incidence of the follicular variant of papillary carcinoma was noticed between 2000-2009, compared to 1990-2000. An increased incidence of small tumors was also found (6.66%, 1990-1999 vs. 23.5%, 2000-2009). The undifferentiated thyroid cancer had a marked decreasing trend (20%, 1990-1999 vs. 3.45%, 2000-2009).
Conclusions: Our study demonstrates an increasing trend in the incidence of thyroid cancer in the last 20 years. This increase is mainly due to the small papillary cancers, by contrast to the undifferentiated thyroid cancers that have a decreasing trend. A better understanding and description of the morphological criteria could explained the increasing incidence of the follicular variant of papillary carcinoma.