Papillary Thyroid Cancer with Bilateral Adrenal Metastases

Background: Papillary thyroid cancer is the most common type of thyroid malignancy and has an excellent prognosis. Distant organ metastasis is rare. Bilateral adrenal metastases with iodine uptake has not been described before. Patient Findings: A 47-year-old woman presented for evaluation because of severe right upper arm pain and weakness. Magnetic resonance imaging of the thoracic spine showed a compression fracture at the third thoracic vertebra associated with a soft tissue mass. Computed tomography (CT)-guided biopsy of the mass showed metastatic papillary thyroid carcinoma. Ultrasonography of the neck showed an enlarged right thyroid lobe with cervical lymphadenopathy. A high-resolution CT scan of the chest showed multiple bilateral pulmonary nodules. Treatment included total thyroidectomy and lymph node dissection, external beam radiation to the thoracic spine, and I-131 therapy. Initial whole body I-131 scintigraphy showed faint uptake in the right upper abdomen, interpreted as a sign of physiologic bowel activity; however, repeat whole body I-131 scintigraphy showed increased uptake in both adrenal glands, consistent with metastatic disease. Serial abdominal CT scans showed progressively enlarging bilateral adrenal masses. Despite additional treatment with I-131, the patient's disease progressed at all metastatic sites. Summary: This patient had bilateral adrenal metastases from advanced papillary thyroid cancer with distant metastasis to lung and bone at initial presentation and poor response to repeated I-131 therapy. Unilateral adrenal metastasis from thyroid cancer has been described previously in six cases; this is the first case report of bilateral adrenal metastases. Conclusions: Bilateral adrenal metastasis is rare in papillary thyroid cancer. Elevated abdominal uptake of I-131 in a high-risk patient may be a sign of abdominal metastatic disease.