Size Dependent Ultrasound Characteristics in Histologically Confirmed Papillary Thyroid Carcinomas: A Multivariate Analysis

Background: Epidemiologic data revealed an increasing incidence of papillary carcinomas (PTCs) in the German population. There is some evidence that the size of resected PTCs has decreased during the last few years. Purpose: The aim of the present study was to test the hypothesis that the sonographic characteristics of PTCs vary with size. Material/Methods: Consecutive PTCs were histologically confirmed in 41 patients. Ultrasound examinations of these 50 PTCs were reevaluated retrospectively and classified according to five sonographic criteria. Results: It could be shown that the sonographic shape (p < 0.001), the contour (p = 0.024), the structure (p = 0.04), the echogenicity (p < 0.001) and calcifications (p = 0.008) varied with the size of the neoplasms. By factoranalysis a factor FPTC with an eigenvalue of 1.89 could be extracted from the data on which the sonographic structure, the ontour and the presence of calcifications had the strongest impact with factorloadings of 0.74, 0.68 and 0.61, respectively. Conclusion: The knowledge of the variation of the ultrasound characteristics should be of assistance for the sonographic classification of PTCs. In this context microcarcinomas usually do not display cystic components. However, they may show microcalcifications. Cystic components, hyperechogenicity and the taller-than-wide sign are predominantly seen in larger PTCs.