Tc-99m MIBI scintigraphy in tall cell variant of papillary thyroid carcinoma with negative radioiodine scan.

We report on a 45-year-old man who had a mass on the wall of the anterior right hemithorax. An excisional biopsy indicated carcinoma metastasis from thyroid malignancy. Tc-99m methoxyisobutyl isonitrile (MIBI) scintigraphy revealed markedly increased activity on the left side of the thyroid and the thoracic wall mass. Postoperative histology revealed a tall cell variant of papillary thyroid carcinoma. Whole body scintigraphy after radioiodine treatment was negative twice. However, Tc-99m MIBI and bone scintigraphy showed multiple soft tissue and bone metastases in the follow-up period. He died 3 years later because of complications of distant lung metastases.