Negative 99mTc-MIBI uptake in a parathyroid carcinoma: A case report

A 34 year old woman with malaise, polyuria and nocturia as well as nausea and vomiting referred to perform a thyroid scan due to right thyroid lobe mass. The scan showed a cold nodule in the right thyroid lobe. Serum calcium of 16.9, serum phosphorus of 1.8 and PTH of 1156 were noticed in laboratory tests. Parathyroid scan with 99mTc-MIBI showed no abnormal tracer activity in the neck and mediastinum in planar and SPECT images. The patient underwent surgery and histopathology confirmed parathyroid carcinoma. To extent of our knowledge, this is one of few cases of negative 99mTc-MIBI uptake parathyroid carcinoma were reported.