Multifocal Metastatic Breast Carcinoma to the Thyroid Gland Histologically Mimicking C Cell Lesions

Abstract

The thyroid gland is an uncommon site of metastatic disease. Renal cell carcinoma is the most common primary source, while metastasis from breast carcinoma is very rare. However, given that thyroid nodules are more common in women, and women with a history of breast cancer are at higher risk of developing thyroid cancer, the possibility of metastatic breast carcinoma must be considered when evaluating a thyroid nodule. We present the case of a 67-year-old woman who presented with dysphonia and dysphagia secondary to multinodular goiter and was found to have multifocal metastatic breast carcinoma in her surgical resection specimen. The histologic appearance focally mimicked C cell hyperplasia and medullary thyroid carcinoma, so immunohistochemistry was critical for establishing the diagnosis. Metastasis to the thyroid should always be included in the differential diagnosis for a thyroid nodule in a patient with a history of previous malignancy.

Thyroid metastases from breast carcinoma: case report and review of literature

“…Magers et al [6] found that metastatic thyroid cancer from breast cancer can cytologically and morphologically mimic primary thyroid cancer on FNAB. Additionally, metastatic breast cancer cells in the thyroid, which mimicked C cell hyperplasia and medullary thyroid carcinoma, were observed in the case of Ghias et al [5]. In our case, FNAB of thyroid showed malignant cells with enlarged nuclei.…”

“…Previous studies have demonstrated that GATA3 and GCDFP15 expression were positively associated with breast carcinoma and breast cancer metastasis [15,16].GATA3 is superior to GCDFP15 in determining the breast origin [17,18]. Ghias et al [5] reported that thyroid metastases cells were positive for ER, GATA3, and were negative for GCDFP, TTF-1, TG and calcitonin. Similar result is also observed in our case.…”

“…In our case, the patient also presented no symptoms related to the thyroid disease. Other studies showed patients with thyroid metastases from breast cancer demonstrated dysphagia and dyspnea [5][6][7][8]. In addition,the US features of thyroid metastases from breast cancer are not speci c. Zhou et al [1] reported that six patients showed heterogeneous echogenicity with scattered microcalci cation, and two patients had hypoechoic solid nodule on US.…”

“…Calcitonin, involved in the parafollicular cells, is associated with medullary thyroid carcinoma [13]. In contrast, above immunohistochemical markers were negative for thyroid metastases [5,14]. On the other hand, considering the history of breast cancer, the immunopro le of breast cancer such as ER, PR, HER2, GATA3 and GCDFP15, should be used to con rm the origin from breast cancer metastasis.…”

“…Generally,the common origins of thyroid metastases seems to be breast cancer and lung cancer in autopsy cases [4]. However, in clinical cases, the most common primary site is the kidney, followed by the breast [5,6]. Recently, with the advent of advanced diagnostic methods such as FNAB and immunohistochemistry(IHC), thyroid metastases have been reported increasingly.…”