Sonographic Findings of Metastatic Disease to the Thyroid

Abstract

The goal of this study was to evaluate the sonographic findings of thyroid metastases arising from non-thyroid primaries. The study over a 5-year period comprised nine patients who had histopathologically proven metastatic disease to the thyroid. Ultrasonography was available in all cases. Ultrasound-guided needle aspiration was performed on 10 suspected nodules as determined by ultrasound. The Ultrasonographic findings were analyzed in two different ways. The first analysis included only those nodules biopsed, and the second analysis included all the nodules, biopsed and non-biopsed. The primary neoplasms were breast carcinoma (n=6), uterine leiomyosarcoma (n=1), cervical carcinoma (n=1), and nasopharyngeal carcinoma (n=1). Excluding 2 nodules, the 8 remaining metastatic nodules exhibited ill-defined hypoechoic character with heterogeneous texture. The other two nodules showed relatively circumscribed iso- or hypo-echoic character with cystic portion. From the analysis of ultrasonographic findings including all thyroid nodules irrespective of pathologic proof, 7 cases - excluding the 2 cases from the 9 cases - showed unilateral or bilateral multiple nodules suspected of metastasis. There was no evidence of microcalcification in any thyroid nodules. In conclusion, the sonographic findings of the thyroid metastatic nodules were not specific, but unilateral or bilateral multiple suspected thyroid nodules without evidence of microcalcification may be suggestive of metastatic nodules among patients with a known primary non-thyroidal tumor.

Nowotwory wtórne ujawniane podczas BAC tarczycy — analiza częstości występowania i charakterystyka obrazu ultrasonograficznego

“…In the literature the typical ultrasound image of secondary tumours is not specified. The most commonly reported are heterogeneous, hypoechoic lesions with blurred margins, often with calcifications [23] or without them [30]. In our material metastatic tumours presented calcifications twice as often as benign lesions, while primary tumours showed calcifications three times more often than benign lesions.…”

“…Early diagnosis including a thyroid FNA result allows the avoidance of unnecessary thyroid surgery in some cases. On the other hand, when analysis is mainly based on biopsy results, the limitation is a frequent impossibility to distinguish primary, especially non-differentiated, thyroid cancers from secondary tumours [11,14,[23][24][25]. In such cases the FNA result indicates only the need to take into account…”

Ultrasonographic Classification of the Metastases to the Thyroid Gland

“…Our results were opposite against the previous studies, which were focused on only focal lesions on thyroid gland. 5,8) In numerous large cohort autopsy studies, the most common primary non-thyroidal origin of thyroid metastases was lung or breast. 1,[10][11][12] These thyroid metastases detected on autopsy tended to be clinically occult.…”

“…[2][3][4] In contrast, the incidence of thyroid metastases ranges from 2% to 24% in the patients affected by widespread malignant neoplasm according to autopsy studies. 5) Some investigators have suggested that thyroid metastases were no longer considered rare. Thyroid metastases arising from non-thyroidal malignancies have been reported in 1.4-3% of patients who underwent surgery for thyroid cancer; 2,6,7) however, the actual number of thyroid metastases may be greater because not all patients undergo surgery.…”

“…5,8) In the studies, the investigators enrolled a small population and analyzed thyroid metastases, representing only focal lesions on the images clinically.…”