Metastatic renal cell carcinoma in the thyroid gland: ultrasonographic features and the diagnostic role of core needle biopsy

Abstract

PurposeThe aims of this study were to present the ultrasonographic (US) features of metastatic renal cell carcinoma (RCC) in the thyroid gland and to evaluate the diagnostic utility of fineneedle aspiration (FNA) and core needle biopsy (CNB).MethodsEight patients with nine metastatic RCC nodules in the thyroid glands who were treated from January 2002 to March 2015 in a single tertiary hospital were consecutively selected and retrospectively reviewed. US features and clinical history were obtained from the institution’s medical database. FNA was performed nine times on eight nodules and CNB was performed six times on six nodules. The diagnostic utility of FNA and CNB was evaluated.ResultsAll nine nodules showed mass formation without diffuse thyroid involvement. On ultrasonography, metastatic RCC nodules were solid (100%), hypoechoic (100%), and ovalshaped nodules with a well-defined smooth margin (88.9%) and increased vascularity (100%, with 55% showing extensive vascularity). No calcifications were noted in any nodules. Lymph node metastasis and direct extension to nearby structures beyond the thyroid gland were not found. One FNA (11%) was able to confirm metastatic RCC, whereas all six CNBs confirmed metastatic RCC.ConclusionMetastatic RCC appears as oval-shaped hypoechoic solid nodules with well-defined smooth margins, no calcifications, and increased vascularity on ultrasonography. Characteristic US features along with a previous history of RCC should raise clinical suspicion, and CNB should be performed to make an accurate diagnosis.

Core-Needle Biopsy Does Not Show Superior Diagnostic Performance to Fine-Needle Aspiration for Diagnosing Thyroid Nodules

“…Fourth, although our findings indicate that CNB cannot be a main diagnostic tool for thyroid nodules, it can still play a role in diagnosing thyroid lymphoma, anaplastic carcinoma, and metastasis from other organs. [28][29][30] In this study, we were unable to evaluate the selective indications of CNB. Finally, we did not assess diagnostic performance for predicting neoplasm because there were only a small number of FNs in this study.…”

Ultrasonographic characteristics of thyroid metastasis from clear cell renal cell carcinoma

“…Previous studies of ultrasound imaging characteristics of thyroid metastasis from ccRCC are summarized (Table 1 ). [ 7 – 11 ] The results showed that the thyroid metastasis from ccRCC generally appeared as solid or solid-cystic nodules on ultrasound images, which could be single or multiple, mostly occurring in irregular shapes with heterogeneous internal echo, and were generally accompanied with calcifications or liquidation. Besides, CDFI generally showed rich blood flow signals and high-resistive Doppler waveforms.…”

Metastatic Renal Cell Cancer to Thyroid Diagnosed by Endoscopic Ultrasound Guided Fine Needle Aspiration Technique

“…In 2015, a multi-institutional study of 62 cases of secondary thyroid cancer showed that FNA biopsy has a sensitivity and specificity of 80% and 93%, respectively [ 1 ]. In 2016, Song et al [ 8 ] described the transcutaneous ultrasonographic features and the diagnostic role of core needle biopsy in 8 patients with metastatic RCC nodule. The ultrasonographic features of metastatic RCC showed solid, hypoechoic, noncalcified nodules in all cases.…”