Category: Thyroid

Monitor: 5

5 - A case of isolated metastatic renal cell carcinoma to the thyroid, 21 years after the initial diagnosis

Friday, Apr 26
11:00 AM – 11:30 AM

Objective : Less than 3 % of malignancies of thyroid gland are due to metastatic disease. We present a rare case of renal cell cancer (RCC) with isolated metastasis to the thyroid, 21 years after the initial diagnosis. 


Methods :

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Results :

N/A


Discussion :

A 74 yo male presented to the Endocrinology clinic in July 2018 for non toxic multinodular goiter incidentally discovered on CT scan of the chest showing an asymmetrically enlarged left thyroid lobe with 2.1 cm hypodense nodule with micro-calcifications. A thyroid ultrasound showed an irregular solid nodule at the junction of isthmus and left lobe with increased vascularity measuring 2 X 1.8 X 1.3 cm. The left lobe was entirely replaced by a lobulated heterogenous solid nodule, taller than wide, with increased vascularity measuring 6 X 3.2 X 3.2 cm, with calcifications. The patient was euthyroid and asymptomatic. He underwent FNA biopsy of both the left and the isthmic nodules. Cytology showed cells with clear and granular cytoplasm suggestive of metastatic RCC, clear cell type. Patient had a previous history of RCC diagnosed in 1997 and treated initially with radical right nephrectomy. In 2001 he was found to have left RCC treated with partial left nephrectomy. In 2008 he had local recurrence which required another left partial nephrectomy with pathology showing RCC with clear surgical margins and no vascular invasion. The RCC was considered in remission until the metastatic involvement of the thyroid was diagnosed. Since there was no evidence of other metastatic disease, he underwent left hemithyroidectomy and isthmus resection. A biopsy of the right thyroid lobe done intraoperatively did not show evidence of metastatic disease. Final pathology confirmed metastatic RCC clear cell type. Patient did not have any surgical complication and did not require thyroid hormone replacement post-surgery.


Conclusion :

Metastases to the thyroid gland are uncommon due to rapid arterial blood supply, high oxygen and iodine concentration.  Metastases from non-thyroid malignancies (NTM) to the thyroid are reported to be present in 1.4-3% of the patients who undergo surgeries for thyroid malignancies. Females have slightly high prevalence of NTM. The most common primary sites are RCC, followed by lung, head and neck and breast cancers. Diagnosis is done by FNA biopsy. NTM are usually managed surgically. Total thyroidectomy is the mainstay of treatment, but hemithyroidectomy is also appropriate when the tumor is confined to one lobe. The mean interval between diagnosis of primary RCC and thyroid metastases is about 9 years. Our patient was diagnosed with metastasis to the thyroid nearly 21 years after the first diagnosis of RCC.

Madhura Borikar

Fellow
UAMS
Little Rock, Arkansas

Madhura Borikar is a first year Endocrinology fellow.

Michael W. Johnson

Assistant Chief, Pathology and Laboratory Medicine Service, Anatomic Division
Central Arkansas Veterans Healthcare System
Little Rock, Arkansas

Dr. Michael Johnson is an assistant Chief, Pathology and Laboratory Medicine Service, Anatomic Division of Central Arkansas Veterans Healthcare System.

Elena Ambrogini

Assistant Professor Division of Endocrinology and Metabolism
University of Arkansas for Medical Sciences Central Arkansas Veterans Healthcare System
Little Rock, Arkansas

Dr. Elena Ambrogini is an assistant Professor Division of Endocrinology and Metabolism at University of Arkansas for Medical Sciences Central Arkansas Veterans Healthcare System.

Madhura Borikar

Fellow
UAMS
Little Rock, Arkansas

Madhura Borikar is a first year Endocrinology fellow.