Ultrasound Evaluation of Parathyroid Adenoma with Co-Existent Thyroid Pathology

Abstract

The diagnostic challenge in the localization of abnormal parathyroids in hyperparathyroidism is further accentuated in cases with coexistent thyroid abnormalities. The most common and most challenging of these are multinodular goitres seen in 32.7%, thyroiditis in 3.8%, thyroid adenoma in 3.8% and thyroid carcinoma in 1.9% coexisting with parathyroid adenoma (Zheng et al. 2007). The sensitivity and specificity of parathyroid localization on both sestamibi and ultrasound scans are compromised (Zheng et al. 2007). Thyroid nodules such as follicular adenomas take up the technetium contrast and are diagnosed as false positive for parathyroid nodules on a sestamibi scan. On ultrasound, multiple thyroid nodules may limit a clear and thorough assessment of the thyroid and parathyroid area for the evaluation of the parathyroids. Very large multinodular goitres extending into the mediastinum may cause alteration in the position of the adjacent parathyroid glands and may not be well evaluated on ultrasound. Concomitant suspicious thyroid nodules require a cytological diagnosis for appropriate surgical planning (Cuhaci et al. 2017a). Further imaging by computed tomography (4D CT) is required in select cases. This chapter aims to indicate the need for clinical awareness of concomitant PHPT and thyroid disease. A precise and comprehensive preoperative clinical diagnosis offers the possibility of synchronous treatment of associated thyroid abnormalities via minimally invasive surgical approach with additional resection of ipsilateral thyroid in select patients. BNE or bilateral neck exploration may be required in some patients and the management and choice of surgery depend on the associated thyroid abnormalities and often parathyroidectomy is combined with thyroidectomy in cases of associated thyroid nodules with abnormal cytopathology findings or large multinodular goitres with pressure symptoms or aesthetic concerns.