Sonographic Features Suggestive of Papillary Thyroid Carcinoma

Research Article

Austin J Endocrinol Diabetes. 2014;1(6): 1027.

Sonographic Features Suggestive of Papillary Thyroid Carcinoma

Sheikh HI1, Toubi AU2, Shechner CA3 and Saiegh LE1,3*

1Department of Internal Medicine B, Bnai-Zion Medical Center, Israel

2Ultrasound unit, Radiology Department, Bnai-Zion Medical Center, Israel

3Endocrinology Departments, Bnai-Zion Medical Center, Israel

*Corresponding author: Saiegh LE, Endocrinology Department, Bnai-Zion Medical Center, Israel,

Received: August 08, 2014; Accepted: October 09, 2014; Published: October 10, 2014


Aim: To examine the prevalence and the diagnostic value of different ultrasonographic features in thyroid papillary carcinoma.

Methods: The sample of the study consisted of 74 patients, 40 of them have had the diagnosis of papillary cancer on ultrasound guided fine-needle-aspiration, while the other 34 patients have had the diagnosis of benign colloid nodule. The ultrasonographic images were re-reviewed and several features were evaluated and correlated with the final cytology.

Results: The ultrasonographic features that have been associated with malignancy were: non-homogenous hypo-echogenicity (P<0.017), poorly defined margins (P<0.008), presence of micro-calcifications (P<0.001) and lobular contour (P<0.05). The presence of colloid was associated with benignity (P<0.001). On the other hand, size of nodule, number of nodules and presence of macro-calcifications were not associated with papillary carcinoma.

Conclusions: In a thyroid nodule, the ultrasonographic features that were significantly associated with papillary cancer were: non-homogenous hypo-echogenicity, poorly defined margins, presence of micro-calcifications and lobular contour.

Keywords: Ultrasound; Fine-needle aspiration; Papillary cancer


Thyroid nodule is a common finding. It could be revealed in approximately 4-8% of adult people by palpation and in 50% by post mortem histological examination. The prevalence of thyroid nodules increases with age [1]. Risk factors that predispose for thyroid cancer are: male gender, age below 20 or above 60, family history and childhood neck irradiation.

Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancy in children and adults, as it accounts for 80% of all thyroid malignancy cases.

Fine needle aspiration (FNA) is the most important initial diagnostic test of thyroid nodule. The accuracy of this test is between 70-97% [1]. Approximately 70% of tests are benign, 4% malignant, 10% suspicious and 10% of the tests are interpreted as non-conclusive [2].

Ultrasound (US) is an important tool for evaluation of a thyroid nodule. The current recommendation is to perform FNA with ultrasound guidance for nodules that can’t be palpated. But, many researches have shown that ultrasound guidance is important in palpable nodules as well, as it increases the accuracy of the test compared to FNA alone.

Many studies have been carried out in order to distinguish between benign and malignant nodules according to different ultrasonographic features, but characterization of nodules as either benign or malignant remains problematic because of considerable overlap in ultrasonographic features. Presence of micro-calcifications, hypo-echogenicity, nodule size, irregular borders, absence of “halo sign”, central vascularity, one nodule versus multiple and solid nodule versus cystic one, all have shown in some studies to be correlated with malignancy [3,4]. However, the sensitivity and specificity of these findings were not high enough. So, radiologic diagnosis and distinction between benign and malignant nodules are often not possible. These features are used mainly to guide the cytopathologist which nodule to examine by FNA in the cases when multiple nodules exist.

Although there have been multiple studies describing the ultrasonographic features of papillary thyroid carcinoma, very few have examined all the features in a single study.

The purpose of the current study is to examine the prevalence and the diagnostic value of different ultrasonographic features in thyroid papillary carcinoma.

Material and Methods

We retrospectively reviewed the ultrasonographic features of cases of papillary thyroid carcinoma and benign nodules imaged over a year (January 2012 to December 2012) at our institution (Bnai-Zion Medical Center, Haifa, Israel). Our study comprises 74 patients, 40 of them were diagnosed to have papillary cancer, while the other 34 had harbored a benign colloid nodule by cytology. Thyroid US was performed by a single skilled radiologist with GE Logiq 9 ultrasound machine using 10 MHz linear transducer. In real time, the radiologist recognized the nodule and the cytologist inserted the needle when the same radiologist still imaging the nodule. FNA was performed using a 23-guage needle, and in each case, an average of two passes was carried out for each nodule.

Re-reviewing the ultrasonographic images was performed in a “blind” manner, without any prior knowledge of the cytological interpretation of each case.

Different ultrasonographic features were evaluated in each image: The feature “echogenicity” was sorted as hypo echoic, hyper echoic, isoechoic, non homogeneous hypo echoic, non homogenous hyper echoic or non homogenous isoechoic nodule. The feature “echo texture” was sorted as dominant solid, dominant cystic or mixed nodule. We also evaluated the presence of hyper-echoic echogenecities such as micro-calcifications (defined as punctuate echogenic foci with or without acoustic shadowing). Macro-calcifications (defined as course irregular hype rechoic foci casting acoustic shadowing), colloid matter (tiny echo genic foci with a posterior comet-tail or ring down artifact). The feature “nodule margins” was sorted as well defined (with or without halo- defined as a thin rim of decreased echogenicity surrounding the neoplasm) or not defined. The feature “nodule size” was sorted as either less than 1cm, between 1-2cm, between 2-3cm, and more than 3cm. The feature “number of nodules” was sorted as one nodule versus multiple nodules. The feature “nodule contour” was sorted as symmetrical round, lobular or elongated in transitional section.

The prevalence of each feature was examined and was correlated with cytological interpretation.

Statistical analysis was carried out using the statistical software SPSS 15. Statistical comparison of the various parameters and features was performed by using the test 2χ and the student’s t-test. P-values less than 0.05 were considered statistically significant.

The study was performed according to the Declaration of Helsinki and approved by the institutional ethics committee.


The sample of the study consisted of 74 patients, 40 (54.1%) of them have had the diagnosis of papillary cancer on US guided FNA, while the other 34 (45.9%) patients have the diagnosis of benign colloid nodule.

Regarding the ultrasonographic features: number of nodules, nodule size and macro-calcifications, the current study showed none to be significantly associated with papillary cancer. On the other hand, we found that the feature “non homogeneous hypo echoic” nodule (Figure 1) was significantly associated with malignancy with sensitivity of 92.5%, negative predictive value of 76.92% and a positive predictive value of 60.65% (P<0.017). The feature “poorly defined margins” (Figure 2) was also significantly associated with malignancy with sensitivity of 92.5%, specificity of 32.35%, negative predictive value of 78.57% and positive predictive value of 61.66% (P<0.008). A statistically significant association with malignancy was also observed for the presence of micro-calcifications (Figure 3) and lobular contour (Figure 2) with a specificity of 100% and 91.17% respectively, positive predictive value of 100% and 78.57% respectively (P<0.001, P<0.05 respectively).