title: Diffuse metastasis to the thyroid: unique ultrasonographic finding and clinical correlation.
abstract: Cases of metastases to the thyroid gland seem to be increasing in recent years. The clinical and ultrasonographic findings of diffuse metastases have been sparsely reported. Thirteen cases of diffuse metastases to the thyroid gland were documented by thyroid ultrasonography-guided fine needle aspiration cytology between 2004 and 2013. We retrospectively reviewed the patients with diffuse thyroid metastases. The most common primary site was the lung (n=9), followed by unknown origin cancers (n=2), cholangiocarcinoma (n=1), and penile cancer (n=1). Eleven patients were incidentally found to have thyroid metastases via surveillance or staging FDG-PET. Other 2 patients were diagnosed during work-up for hypothyroidism and palpable cervical lymph nodes. On ultrasonography, the echogenicity of the enlarged thyroid gland was heterogeneously hypoechoic or isoechoic, and reticular pattern internal hypoechoic lines were observed without increased vascularity found by power Doppler ultrasonography (3 right lobe, 2 left lobe, and 8 both lobes). In the 8 patients who had involvement of both lobes, 3 had hypothyroidism. In conclusion, ultrasonographic finding of diffuse metastasis is a diffusely enlarged heterogeneous thyroid with reticular pattern internal hypoechoic lines. Thyroid function testing should be performed in all patients with diffuse thyroid metastases, especially those with bilateral lobe involvement.
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Hee Kyung
authors.identifier: 0000-0002-1617-3171
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Pathology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Sung Sun
authors.identifier: 0000-0002-8569-2178
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Chan Young
authors.identifier: 0000-0002-3513-3052
authors.initials: CY
authors.lastname: Oak
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Soo Jeong
authors.identifier: 0000-0002-4865-3460
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Jee Hee
authors.identifier: 0000-0002-5919-6162
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Ho-Cheol
authors.identifier: 0000-0002-0448-1345
authors.initials: HC
authors.lastname: Kang
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000473:pathology; D044963:Biopsy, Fine-Needle; D018281:Cholangiocarcinoma / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007037:Hypothyroidism / Q000150:complications; D008175:Lung Neoplasms / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010412:Penile Neoplasms / Q000473:pathology; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000000981:diagnostic imaging* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D014463:Ultrasonography
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Diffuse; Fine Needle Aspiration Cytology; Metastasis; Thyroid; Ultrasonography