Unilateral adrenal mass as the sole initial manifestation of differentiated thyroid cancer

Unilateral adrenal metastases without disseminated disease has rarely been reported in differentiated thyroid carcinoma (DTC). A 72-year-old female presented with vague abdominal discomfort and loss of appetite of 2 months duration. She had undergone left hemithyroidectomy for a benign thyroid nodule 18 years ago. A contrast CT of the abdomen showed a large left adrenal mass measuring 11×9 cm, suspicious of adrenocortical carcinoma. Hormonal evaluation was in keeping with a non-functional tumour. The patient underwent left adrenalectomy, histopathology of which revealed metastatic well-differentiated thyroid carcinoma. Ultrasound of thyroid done postoperatively showed a subcentimetric hypoechoic lesion with increased vascularity and microcalcifications in the right thyroid bed. Histopathology from a completion thyroidectomy specimen was consistent with follicular variant of papillary thyroid carcinoma. She was treated with high-dose radioiodine ablation therapy and has remained disease-free on follow-up for more than a year.