Destructive thyroiditis secondary to a metastasis
A 62-YEAR-OLD CHINESE WOMAN was admitted with a 1 month history of a progressively enlarging left thyroid nodule associated with generalized malaise, weight loss, dysphagia, and vomiting. She had a history of left modified radical mastectomy for poorly differentiated ductal carcinoma of the left breast (T2 N1 M0) 4 years ago. Physical examination showed a clinically solitary firm left thyroid nodule measuring 4 cm in size. Her serum thyrotropin was less than 0.03 mIU/L (normal range, 0.35-5.5 mIU/L) and her free thyroxine was 26 pmol/L (normal range, 10-19 pmol/L). Erythrocyte sedimentation rate was 10 mm in 1 hour (normal, ,20 mm/hr). Both antimicrosomal and antithyroglobulin antibodies were within normal limit. Fine-needle aspiration cytology confirmed metastatic adenocarcinoma. Technetium thyroid scan revealed diffuse decreased in tracer uptake over left thyroid lobe and normal uptake in the right lobe of thyroid gland (Fig. 1). In view of the persistent symptoms, left thyroid lobectomy was performed for palliation and pathology confirmed metastatic adenocarcinoma from the breast (Fig. 2). She was discharged 2 days after surgery and was able to tolerate a normal diet. At 1 month after surgery, free thyroxine was 10 pmol/L and thyrotropin was 1.3 mIU/L. A bone scan subsequently revealed multiple bone metastases and chemotherapeutic agents were administered. However, she developed pancytopenia after the second course of chemotherapy and died of septicemia 3 months after the thyroidectomy.