Standardized Ultrasound Report for Thyroid Nodules: The Endocrinologist's Viewpoint

Abstract

Background: Ultrasonography (US) plays a crucial role in the diagnostic management of thyroid nodules, but its widespread use in clinical practice might generate heterogeneity in ultrasound reports.

Objectives: The aims of the study were to propose (a) a standardized lexicon for description of thyroid nodules in order to reduce US reports of interobserver variability and (b) a US classification system of suspicion for thyroid nodules in order to promote a uniform management of thyroid nodules.

Methods: RELEVANT PUBLISHED ARTICLES WERE IDENTIFIED BY SEARCHING MEDLINE AT PUBMED COMBINING THE FOLLOWING SEARCH TERMS: ultrasonography, thyroid, nodule, malignancy, carcinoma, and classification system. Results were supplemented with our data and experience.

Results: A STANDARDIZED US REPORT SHOULD ALWAYS DOCUMENT POSITION, EXTRACAPSULAR RELATIONSHIPS, NUMBER, AND THE FOLLOWING CHARACTERISTICS OF EACH THYROID LESION: shape, internal content, echogenicity, echotexture, presence of calcifications, margins, vascularity, and size. Combining the previous US features, each thyroid nodule can be tentatively classified as: malignant, suspicious for malignancy, borderline, probably benign, and benign.

Conclusions: We propose a standardized US report and a tentative US classification system that may become helpful for endocrinologists dealing with thyroid nodules in their clinical practice. The proposed classification does not allow to bypass the required cytological confirmation, but may become useful in identifying the lesions with a lower risk of neoplasm.

Keywords: Carcinoma; Elastography; Malignancy; Nodule; Thyroid; Tumor; Ultrasonography; Ultrasound.

Fig. 1

US images showing the main features of the thyroid nodules. 1.1 Ovoid nodule deforming thyroid capsule. 1.2 Nodule infiltrating thyroid capsule (see interruption of hyperechoic capsule). 1.3 Tumoral nodule invading perithyroidal tissue (see invasion of jugular vein). 1.4 Solid round nodule. 1.5 Markedly hypoechoic nodule with ‘taller-than-wide’ shape. 1.6 Large nodule with irregular shape. 1.7 Homogeneous, isoechoic, solid nodule with well-defined margins and thin halo sign. 1.8 Mixed nodule presenting predominantly solid internal content. 1.9 Mixed nodule presenting predominantly cystic internal content. 1.10 Anechoic pure cystic nodule. 1.11 Spongiform nodule with regular margins and finely inhomogeneous echostructure (see internal bright hyperechoic spots). 1.12 Hypoechoic nodule. 1.13 Hyperechoic nodule. 1.14 Nodule with markedly inhomogeneous echostructure. 1.15 Laser-treated nodule with inhomogeneous echostructure (see cavitations and hyperechoic scars). 1.16 Nodule containing microcalcifications. 1.17 Nodule containing coarse macrocalcifications (see posterior acoustic shadow). 1.18 Nodule with peripheral ‘eggshell’ calcification. 1.19 Nodule presenting ill-defined margins. 1.20 Nodule with spiculated margins. 1.21 Nodule presenting microlobulated edges. 1.22 Nodule with thick irregular halo. 1.23 Nodule presenting perinodular flow (PD). 1.24 Nodule with moderate intranodular flow (PD). 1.25 Nodule with moderate peri-intranodular flow (CD). 1.26 Nodule with increased intranodular flow (CD). 1.27 Nodule with increased peri-intranodular flow (PD). 1.28 US-E evaluation of predominantly elastic nodule (see prevalence of ‘soft’ areas within the nodule).