Optimal imaging modality for diagnosis of parathyroid adenoma: Case report and review of the literature

• Published in: Journal of clinical and translational endocrinology case reports Vol. 17; p. 100065
• Main Authors: Tsai, Karen, Liang, Tom Z., Grant, Edward G., Swanson, Mark S., Barnett, Braden
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-09-2020; Elsevier
• Subjects: Hypercalcemia; Hyperparathyroidism; Intrathyroid parathyroid adenoma; Parathyroid adenoma; Parathyroidectomy; PTH; Hypercalcemia; Parathyroid adenoma; Parathyroidectomy; Intrathyroid parathyroid adenoma; PTH; Hyperparathyroidism
• ISSN: 2214-6245; 2214-6245
• DOI: 10.1016/j.jecr.2020.100065

Current standard modalities for imaging intrathyroidal parathyroid lesions include ultrasound and Tc99m-sestamibi, 4-dimensional CT and MRI. Imaging is important because it can be used for characterization, surgical planning and accurate localization of abnormal parathyroid glands. In rare circumstances if imaging is equivocal, selective venous sampling of PTH levels can be used. Studies suggest potential clinical utility in the use of 18F-Fluorocholine PET/CT (FCH PET/CT) and 11C-choline PET/CT in identifying parathyroid adenomas. The data on contrast enhanced ultrasound (CEUS) is limited but our case shows that it can be a promising adjuvant imaging in evaluating intrathyroid parathyroid adenomas.
We report a case of a 32-year-old female with no significant past medical history who was incidentally found to have asymptomatic hypercalcemia. She was recommended to pursue a parathyroidectomy to avoid long term complications of chronic hyperparathyroidism. Head and neck ultrasound showed a well-defined, very hypoechoic nodule measuring 7 x 6 x 6mm in the posterior mid/lower pole region of the right lobe of thyroid with a largely intrathyroidal appearance and another right posterior lesion. The blood supply by Doppler of the 7mm right lower pole nodule appeared to arise from a polar artery (extrathyroidal blood supply) suggesting a parathyroid lesion. A contrast-enhanced head and neck ultrasound confirmed an intrathyroid parathyroid adenoma. Successful removal of intrathyroid parathyroid adenoma was performed with intraoperative frozen section confirming parathyroid tissue. Fifteen-minute post-excision parathyroid hormone (PTH), 2 month-post-operative calcium level, and PTH decreased.
With definitive confirmation and localization of the abnormal parathyroid gland using CEUS, more patients can be treated with minimally invasive parathyroidectomy and benefit from the advantages of this operative technique.