Occult thyroid carcinoma presenting with clinically apparent metastasis is rare and is a diagnostic challenge. Here we report a 68-year-old male who presented with a left side chest wall mass of one year duration. The mass showed rapid enlargement at the latter end of its course, following an initial asymptomatic period. Imaging studies showed a soft tissue mass eroding into several ribs. Wide local excision with primary reconstruction was performed. Histological studies and immune staining revealed metastasis from a follicular thyroid carcinoma. Total thyroidectomy followed, confirming the diagnosis. Post-operatively radio isotope ablation (I131) was done. A suppression dose of thyroxin was continued with regular thyroglobulin assays. Painful bone metastasis responded well to analgesics, bisphosphonates and external beam radiotherapy. Follicular carcinoma comprise 10–15% of thyroid malignancies. Localized thyroid carcinoma has a very good prognosis, 10 year survival rates reducing by 50% with metastatic disease. Commonly thyroid cancer presents as detectable thyroid nodules, 25% having metastasis. In contrast metastatic manifestations are reported in less than 5% of occult thyroid cancers.
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