Solitary Thyroid Metastasis of Renal Clear Cell Carcinoma: Report of a Case

Abstract

A case of solitary thyroid metastasis of renal clear cell carcinoma is described. The patient was a 77-year-old Japanese woman, who was referred to our department after a thyroid tumor was identified in May 1999. She had a history of renal clear cell carcinoma of the left kidney, which had been partially resected 3 years previously. Ultrasound sonography demonstrated that a well-demarcated hypoechoic mass containing high-echo spots representing small calcifications, which measured 45 x 34 x 31 mm in size, occupied the left lobe. Computed tomography revealed a low-density mass containing small calcifications. The results of preoperative fine-needle aspiration cytology strongly suggested a clear cell carcinoma metastasizing to the thyroid. A left hemithyroidectomy was performed on July 27, 1999. A histological examination revealed that the neoplasm was composed of tumor cells with abundant clear cytoplasm and round nuclei. The histological characteristics of this thyroid tumor were virtually identical to the renal cell carcinoma resected 3 years previously. Thyroglobulin stained negatively in the clear cells of the resected thyroid tumor in an immunohistochemical analysis. Clinically, the thyroid gland is a rare site of tumor metastasis; however, we should also consider the possibility of metastasis in the case of thyroid tumor patients with a history of renal cell carcinoma.

Renal Cell Carcinoma Metastatic to Follicular Adenoma of the Thyroid Gland

“…After surgical management, the administration of interferon is recommended for renal cell carcinoma. 14 As shown above, immunohistochemical staining can be a great help in the differential diagnosis. Therefore, we recommended that a cell block, using aspirated samples of the thyroid lesions, be made in the case of patients with a prior history of a malignant tumor in other organs.…”

Thyroid Metastasis of Renal Cell Carcinoma

“…5,10 In any patient with a previous history of malignancy, no matter how remote that history is, a new thyroid mass should be considered recurrent malignant until proved otherwise. 11 It is reported that making diagnosis of metastatic thyroid tumors is difficult and challenging due to the long time period between diagnosis of the primary tumor and detecting metastasis, the presence of small solitary lesions in the thyroid gland and that most cases are asymptomatic.…”

Thyroid Metastases from Gallbladder Cancer

“…Different reports suggest that the most common primary sites are the kidneys, lung, breast, and gastrointestinal tract. [11][12][13][14][15][16] Hematogenous and lymphogenous pathways are considered the route of metastases to the thyroid and have been demonstrated to occur as late as 10 years following resection of the primary tumor.…”