What are the indications for Ultrasound of the thyroid gland parathyroid glands and neck lymph nodes?
US of the neck is commonly used to both characterize and localize palpable neck lesions, and to guide fine needle aspiration (FNA). Specifically, US of the thyroid gland can be used to (1) determine the echotexture of the gland and assess for the presence of a nodule, (2) assess nodule characteristics to determine the need for FNA, (3) follow up thyroid nodule size, (4) screen for occult thyroid cancer in high risk patients, and (5) guide FNA of thyroid nodules. Sonographic evaluation of cervical lymph nodes is commonly performed to detect metastatic disease in patients with a history of malignancy, and to examine palpable nodes for malignant features and guide FNA of abnormal-appearing nodes.
Primary hyperparathyroidism is the most frequent indication for performing US of the parathyroid glands. This condition leads to accelerated bone destruction, renal stone formation, and elevated serum calcium levels and is most commonly diagnosed in the fifth through seventh decades of life. Most cases of primary hyperparathyroidism are caused by a single parathyroid adenoma (89%). Other causes include hyperplasia of all four glands (6%), double adenomas (4%), and, rarely, parathyroid carcinoma. In most instances, parathyroid adenomas are sporadic. There is an increased incidence of parathyroid hyperplasia in patients with multiple endocrine neoplasia (MEN) syndromes.