Purpose: Prospective studies of patients with hyperparathyroidism are warranted to determine the prevalence of concurrent thyroid disease applying the current standard of pre-operative radioscintigraphic and sonographic imaging of the neck. Timely diagnosis and treatment of co-existing thyroid disease is advantageous given the well-established increased morbidity associated with a second neck exploration. The purpose of this study is to determine the prevalence and specific type of thyroid disease in patients with hyperparathyroidism, and to determine the frequency with which the presence of thyroid disease alters the treatment plan for patients with hyperparathyroidism.

Research Design: This will be a prospective single arm observational study of up to 200 military health care beneficiaries over the age of 18 years with primary and secondary hyperparathyroidism scheduled to undergo parathyroid resection.

Methodology: Patients will undergo standard pre-operative imaging of the neck including ultrasonography and 99mTc-sestamibi scintigraphy. An operative plan will be developed based on the information obtained from history, physical examination, laboratory studies, and imaging studies. The number and type of thyroid disease in these patients will be determined based on these non-invasive studies (Objective A). A change in the otherwise standard treatment will include those patients having partial or complete resections of their thyroid glands because: a) the patients would have undergone minimally invasive surgery if not for the results of the imaging studies, and, b) the patients who would have undergone 3 ½ gland parathyroidectomy if not for the results of the imaging studies (Objective B).

Inclusion Criteria:

Patients with hyperparathyroidism and appropriate indications for operation

• Patients over 18 years of age and capable of providing informed consent
• Each patient must provide written informed consent prior to entering the study.

Exclusion Criteria:

• Patients who have previously undergone thyroid or parathyroid operation
• Patients with medullary thyroid carcinoma and hyperparathyroidism or suspected multiple endocrine neoplasm syndrome

200 military health care beneficiaries over the age of 18 years with primary and secondary hyperparathyroidism scheduled to undergo parathyroid resection.