A 70 yrs old male was incidentally found to have hypercalcemia, serum calcium level of 11.9 mg/dl (normal is 8.9 to 10.3). His past medical history included hypothyroidism, prostate carcinoma, atrial fibrillation, type 2 diabetes mellitus, gout, hyperlipidemia, osteoarthritis, migraine and glaucoma. He was found to have an intact PTH level of 373 pg/ml (normal is 16-87) and normal renal function.
Tc-99m Sestimbi scan was performed to localize the probable parathyroid adenoma.

Early and delayed planar images of the neck acquired after intravenous administration of 25.0 mCi of Tc-99m Sestamibi showed a persistent focus of increased uptake at the inferior pole of the left lobe of thyroid, suspicious for a parathyroid adenoma. Focal uptake was also seen in the left axillary and pectoral nodes.

Early SPECT-CT was also acquired and showed the focal abnormal neck uptake to correspond to an abnormal soft tissue density posterior to the left lobe of thyroid. A 1.5 cm parathyroid adenoma was removed from this region at surgery and the intact PTH level dropped to 29 pg/ml.

The axillary uptake corresponded to normal left axillary lymph nodes and felt to be physiologic (secondary to dose inflitration and lymphatic migration) as the tracer was injected in the left antecubital vein.

1. Comparison of SPECT/CT, SPECT, and planar imaging with single- and dual-phase (99m)Tc-sestamibi parathyroid scintigraphy. Lavely WC, Goetze S, Friedman KP, Leal JP, Zhang Z, Garret-Mayer E, Dackiw AP, Tufano RP, Zeiger MA, Ziessman HA. J Nucl Med. 2007 Jul;48(7):1084-9.

2. The value of 99mTc-sestamibi SPECT/CT over conventional SPECT in the evaluation of parathyroid adenomas or hyperplasia. Gayed IW, Kim EE, Broussard WF, Evans D, Lee J, Broemeling LD, Ochoa BB, Moxley DM, Erwin WD, Podoloff DA. J Nucl Med. 2005 Feb;46(2):248-52.

3. Parathyroid scintigraphy in patients with primary hyperparathyroidism: 99mTc sestamibi SPECT and SPECT/CT. Eslamy HK, Ziessman HA. Radiographics. 2008 Sep-Oct;28(5):1461-76.

This case was compiled by Dr. Niraj Patel, BCM