Occult metastatic follicular thyroid carcinoma masquerading as a soft tissue sarcoma of the gluteal region.

This is a case of an occult follicular thyroid carcinoma in a 61 year old civil servant presenting with bony metastasis to the left iliac bone twenty years after an initial subtotal thyroidectomy. There was a soft tissue mass with associated cup shaped Iytic detruction of the iliac bone and on ultrasound scan the mass was found to be of mixed echogenicity and areas of sonolucencies which were due to necroses. At autopsy, the thyroid gland appeared macroscopically within normal limits but histology confirmed Follicular Thyroid Carcinoma.