Citation: Purbhoo KP, Bombil I and Mpanya D. Ectopic Parathyroid Adenoma Localized by Tc-99m Sestamibi SPECT/CT Localization Prior to Re-operation is Useful. J Mol Biol & Mol Imaging. 2016; 3(1): 1026. J Mol Biol & Mol Imaging - Volume 3 Issue 1 - 2016 ISSN : 2471-0237 | www.austinpublishinggroup.com Purbhoo et al. © All rights are reserved Journal of Molecular Biology and Molecular Imaging Open Access Abstract We present a 31-year old male patient with primary hyperparathyroidism (PHPT), complicated by obstructive uropathy due to a staghorn calculus. He had minimally invasive right lower pole parathyroidectomy (MIP), following localization in the right lower pole of the parathyroid gland, on ultrasound. Post- surgical histology confrmed it to be a lymph node. The serum calcium and PTH levels remained elevated post-operative. Tc-99m methoxyisobutyl isonitrile (Sestamibi) planar imaging showed a focus of uptake superior to the upper pole of the right thyroid gland, that was localized lateral to the right true vocal cord on SPECT/CT. Post- operative histology confrmed a parathyroid adenoma. Keywords: Ectopic parathyroid adenoma; Tc-99m; Sestamibi; Primary hyperparathyroidism; SPECT/CT therefore may reduce surgical failure rate, complication rates, and operative time [1]. Tis is even more important in cases of ectopic parathyroid adenomas in which the surgical approach can difer greatly depending on the position of the adenoma [4]. In cases of recurrence of the disease or failed surgery, localization of adenoma by Sestamibi scan is mandatory [5]. SPECT is increasingly used due to the three-dimensional information it provides and the improved sensitivity for the detection and localization of hyperfunctioning parathyroid lesions [2]. SPECT/ CT can further enhance localization by providing better resolution of surrounding structures, and has the added beneft of a more precise localization of ectopic and mediastinal parathyroid lesions [2]. Ultrasound allows anatomical detection of an enlarged parathyroid gland and accurate localization relative to the thyroid gland, although the presence of co-existing nodular thyroid disease reduces the sensitivity and specifcity [6]. Deep-seated or ectopic adenomas in the neck are poorly visualized with ultrasound. In a study by Patel et al, ultrasound alone detected 64% of all solitary parathyroid adenomas, versus SPECT/CT (90%) [6]. We routinely do SPECT/CT imaging at 20 minutes post tracer injection for more accurate anatomical localization the lesion. If it is posteriorly located Case Presentation A 31-year old male patient with a diagnosis of PHPT was sent to Nuclear Medicine with persistently raised serum calcium and parathyroid hormone (PTH) levels, following MIP. His hyperparathyroidism was complicated by obstructive uropathy, due to a staghorn calculus, for which he had a double J stent in- situ. Te ultrasound done prior to surgery showed an enlarged lesion in the right lower pole of the parathyroid gland. Post-surgical histology confrmed it to be a lymph node. No parathyroid gland was demonstrated. Te serum calcium and PTH levels remained elevated post-operative. 20 mCi (740MBq) Tc-99m Sestamibi planar imaging (Figure 1) showed a solitary focus of uptake superior to the upper pole of the right thyroid gland, suspicious for a parathyroid lesion. Diferential washout of tracer is seen from the immediate to the 3 hour image [black arrows] with a clearer delineation of the lesion on delayed imaging. Single Photon Emission Computed Tomography with CT [SPECT/CT], (Figure 2) demonstrated increased uptake lateral to the right true vocal cord. Te patient had removal of the lesion by MIP confrming a parathyroid adenoma (Figure 3). Te patients’ serum calcium and PTH levels reverted to the normal range post-surgery. Discussion Ectopic parathyroid adenomas are rare and are reported to account for 5–10% of cases of PHPT [1]. Pre-operative localization of hyperfunctioning parathyroid tissue is an essential component if minimally invasive surgery is scheduled. Parathyroid localization has improved with numerous imaging techniques, including Sestamibi scintigraphy, ultrasonography and four-dimensional CT [2]. Sestamibi scintigraphy, ofen with complementary ultrasonography, is considered the imaging method of choice for localizing a parathyroid adenoma in the neck [3]. Tis information facilitates a focused or minimally invasive surgical approach to be used, and Case Report Ectopic Parathyroid Adenoma Localized by Tc-99m Sestamibi SPECT/ CT Localization Prior to Re-operation is Useful Purbhoo KP 1 *, Bombil I 2 and Mpanya D 1 1 Department of Nuclear Medicine and Molecular Imaging, University of the Witwatersrand, Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa 2 Department of Surgery, University of the Witwatersrand, Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa *Corresponding author: Purbhoo KP, Department of Nuclear medicine and molecular imaging, University of the Witwatersrand, P.O Bertsham, Johannesburg 2013, South Africa Received: August 02, 2016; Accepted: August 22, 2016; Published: August 24, 2016 Immediate 20 minutes 3 hours Figure 1: Anterior static Sestamibi images, done immediately, and at 20 minutes and 3 hours show a focal lesion superior and lateral to the right thyroid lobe.