Prevalence of thyroid incidentaloma detected by high-resolution ultrasound and their potential risk of malignancy in healthy individuals in Basrah province

Abstract EN

Background: This study conducted to define the prevalence and potential risk of malignancy of thyroid incidentaloma in a healthy population using high‑resolution ultrasound.

Patients and Methods: A cross‑sectional prospective study between December 2017 and March 2018, included 1200 asymptomatic adults participants (1000 women aged 15–70 years and 200 men aged 19–65 year).

The prevalence of thyroid incidentaloma, their distribution according to age and sex, nodule size, ultrasound characteristics, and risk stratification of malignancy using Thyroid Imaging Reporting and Data System (TI‑RADS) grade were studied.

Fine‑needle aspiration cytology (FNAC) examination was done for some specific patients.

Results: The prevalence of thyroid incidentaloma was 27.3%.

Thyroid incidentaloma were more prevalent in females and elderly people in both sexes mainly in 60–75‑year‑old peoples.

Nodules were solitary in 244 (74.4%) and multiple in 84 (25.6%) patients.

The size of 186 nodules (45.1%) were <5 mm, 112 incidentaloma (27.2%) were 5–10 mm, and 114 (27.6%) were more than 10 mm in size.

Thyroid incidentaloma were cystic in 228 (55.3%), solid in 133 (32.3%), and complex in 51 (12.4%).

Most solid nodules were hyperechoic (84/133, 63.2%), 29 (21.8%) isoechoic, and 20 (15%) were hypoechoic.

92.9% (171/184 solid and mixed nodules) were have well‑defined and regular borders and only 13 nodules (7.1%) have irregular and ill‑defined borders.

Furthermore, 90.7% of solid and mixed nodules have wider than taller diameters.

Microcalcifications were seen in three and macrocalcifications in two solid nodules.

Of 412 incidentaloma, 258 were TI‑RAD 2 score, 136 TI‑RAD 3, and 18 nodules were classified TI‑RAD 4.

TI‑RAD nodules 5 were not detected.

Suspicious incidentalomas of TI‑RAD 4 score were sent for FNAC examination.

Papillary carcinoma detected in four nodules and follicular tumor in eight nodules, three of them proved to be follicular carcinoma.

The rate of malignancy in thyroid incidentaloma was 1.7%.

Conclusion: Thyroid incidentaloma is relatively common, and the majority are benign.

Ultrasound characteristics and size of nodule could be a reliable screening tool for malignant potential of the thyroid nodule.