Papillary thyroid carcinoma associated with parathyroid adenoma detected by pertechnetate-MIBI subtraction scintigraphy.

Two cases of papillary thyroid carcinoma coexisting with a parathyroid adenoma are reported. A double-tracer pertechnetate-MIBI subtraction scan combined with neck ultrasound correctly visualized the site of the parathyroid adenoma despite the presence of thyroid nodule(s) located in the opposite thyroid lobe in one case and in both thyroid lobes in the other case. In both patients, the papillary thyroid carcinoma was cold with Tc-99m pertechnetate and hot with MIBI. Total thyroidectomy and parathyroidectomy of a solitary parathyroid adenoma were performed in both patients. Pertechnetate-MIBI subtraction scanning associated with neck ultrasound appears to be a useful imaging technique to detect parathyroid adenoma before operation in patients with concomitant thyroid nodular disease. A MIBI-hot and Tc-99m pertechnetate-cold thyroid nodule can indicate the possible presence of a malignant lesion.