Prevalence, Clinical and Ultrasonographic Characteristics of Thyroid Incidentalomas

Abstract

High-resolution ultrasonography (US) has made possible the detection of asymptomatic small thyroid nodules. Thyroid incidentalomas have created a clinical dilemma as to how to properly manage such incidental findings. We investigated the prevalence, the clinical and US characteristics, and optimal diagnostic approach to incidentally detected benign and malignant thyroid nodules < 1.5 cm. Retrospective review was done on 1475 patients who had visited Samsung Medical Center, Soul Korea from January 1999 to December 2000. The prevalence of thyroid incidentalomas was 13.4%. The malignancy rate within thyroid incidentalomas was 28.8%. There were no significant differences in age, nodule size and number, thyroid function test, and Tc99m thyroid scan between benign and malignant incidentalomas. US characteristics of solid echostructure, irregular margin, and calcification showed meaningful diagnostic value in detecting malignancy in thyroid incidentalomas (p < 0.05). Most malignant incidentalomas were low stage. In conclusion, occult thyroid cancers are a fairly common finding. There were no significant differences in clinical and laboratory parameters between benign and malignant thyroid nodules <1.5 cm; however, US findings can be used in the decision of optimal management strategies.

High Prevalence of Carcinoma in Ultrasonography-guided Fine Needle Aspiration Cytology of Thyroid Nodules

“…For examples, Frates et al perfomed USgFNAC selectively on patients with nodule larger than 1 cm [9]. In other studies, only thyroid nodules less than 1.5 cm were aspirated by sonographic guidance for cytologic examination [4,8]. However, it has been routine practice at our clinic to refer all patients with incidental thyroid nodules to radiologists.…”

“…Many studies have examined the relationship between sonographic features of thyroid nodules and malignancy [4,8,9]. Recent recommendations suggest FNAC for most nodules greater than 10-15 mm, particularly those with suspected malignancy based on sonographic features and in cases of multiple nodules, FNAC should be based on the sonographic features rather than size of each nodule.…”

“…The number of thyroid incidentalomas is increasing due to widely use of highly sensitive ultrasonography for routine health examinations [4]. Previous studies have reported that incidental thyroid nodules are commonly detected at a rate of 30-50% on sonography [5,6] with a malignancy rate of about 7-15% [7][8][9][10].…”

Estimation of the Release Time from Isolation for Patients with Differentiated Thyroid Cancer Treated with High-dose I-131

“…Recently, the number of thyroid cancer cases detected in Korea has increased dramatically because of the widespread use of high-resolution ultrasonography and fine-needle aspiration cytology [2,3]. Because most patients with differentiated thyroid cancer require HDRIT after surgery, a shortage of available isolation rooms has resulted.…”

Incidental thyroid “PETomas”: clinical significance and novel description of the self-resolving variant of focal FDG-PET thyroid uptake

“…Studies have shown the incidence of such thyroid incidentalomas to be between 19% and 46% for ultrasonography and about 16% for CT and MRI. 8,14 The risk of malignancy in these lesions is relatively low, ranging from 1.5% to 10.0%. 15 With the increasing use of FDG-PET in the evaluation and surveillance of patients with cancer, a substantial number of patients will present with incidentally identified focal uptake within the thyroid, 1 which we refer to as a "PEToma."…”