Metastasis to the Thyroid Gland: A Critical Review

Abstract

BackgroundMetastasis to the thyroid gland from nonthyroid sites is an uncommon clinical presentation in surgical practice. The aim of this review was to assess its incidence management and outcomes.MethodsA literature review was performed to identify reports of metastases to the thyroid gland. Both clinical and autopsy series were included.ResultsMetastases to the gland may be discovered at the time of diagnosis of the primary tumor, after preoperative investigation of a neck mass, or on histologic examination of a thyroidectomy specimen. The most common primary tumors in autopsy studies are from the lung. In clinical series, renal cell carcinoma is most common. For patients with widespread metastases in the setting of an aggressive malignancy, surgery is rarely indicated. However, when patients present with an isolated metastasis diagnosed during follow-up of indolent disease, surgery may achieve control of the central neck and even long-term cure. Other prognosticators include features of the primary tumor, time interval between initial diagnosis and metastasis, and extrathyroid extent of disease.ConclusionsIn patients with thyroid metastases, communication among clinicians treating the thyroid and the index primary tumor is essential. The setting is complex, and decisions must be made considering the features of the primary tumor, overall burden of metastases, and comorbidities. Careful balancing of these factors influences individualized approaches.

Colon cancer metastasis to the thyroid gland: A case report

“…Additionally, immunohistochemistry is crucial for the final diagnosis. Primary thyroid tumors are positive for CK7 and negative for CK20, in contrast to colon cancer metastases, which are positive for CK20 and negative for CK7 [6,11]. In line with literature data, our patient presented increased tumor markers without symptoms, and only four months later was the cervical nodule noticed by the patient.…”

Curious Residents of the Thyroid Gland: Two Case Reports of Colorectal Carcinoma Metastasis by Fine-Needle Aspiration Diagnosis

“…In up to 40% of patients with a thyroid gland metastatic deposit, the thyroid metastasis is the initial presentation, especially in renal cell carcinoma [3,5]. The most fre- quent metastases to the thyroid originate in the kidney, lung or breast [2,3].…”

“…In up to 40% of patients with a thyroid gland metastatic deposit, the thyroid metastasis is the initial presentation, especially in renal cell carcinoma [3,5]. The most fre- quent metastases to the thyroid originate in the kidney, lung or breast [2,3]. Metastases of colorectal adenocarcinoma are rare, accounting for less than 4% of thyroid metastases, with only 52 cases published so far [4,[6][7][8].…”

“…Anaplastic thyroid carcinoma is frequently present in the differential diagnosis. Cytologically, it can be very difficult to distinguish anaplastic thyroid carcinoma from high-grade metastases [2,3].…”

“…In autopsy material from patients with disseminated malignancy, occult metastases are reported to be as high as 25% [2,3].…”