Role of cervical ultrasound in detecting thyroid pathology in primary hyperparathyroidism

Minimally invasive parathyroidectomy for primary hyperparathyroidism is made possible with accurate preoperative imaging. In addition to the detection of parathyroid adenomas, cervical ultrasound also provides concomitant assessment of the thyroid gland, and many surgeons believe that it is essential. However, the incidental identification of thyroid nodules may then subject patients to further workup and potentially invasive thyroid procedures. We sought to determine the long-term consequence of omitting preoperative ultrasound on the development of thyroid pathology and cancer.

At our institution, 222 patients with primary hyperparathyroidism underwent parathyroidectomy without preoperative cervical ultrasound from 1990-2001. Thyroid pathology discovered by follow-up after parathyroidectomy, subsequent biopsy, and surgical interventions were analyzed.

Of the 222 patients who underwent parathyroidectomy, the mean age was 55 ± 1 y and 149 were female (67%). In the course of their follow-up after parathyroidectomy, 13 patients (6%) received a cervical ultrasound, and seven of 13 (3%) underwent fine needle aspiration of a thyroid nodule. Only one of seven (0.4% of all patients) was ultimately diagnosed with thyroid cancer. Four additional patients were discovered to have thyroid malignancies as a result of intraoperative decision making. All five patients are currently alive with an average follow-up time of 14.9 ± 1.6 y. No patients in this series had an unnecessary thyroid intervention.

In patients who underwent parathyroidectomy without a preoperative ultrasound, only a small number (0.4%) were subsequently diagnosed with thyroid cancer. Furthermore, omission of ultrasound during the localization of parathyroid glands does not have a negative impact on the diagnosis of thyroid pathology as all patients who had thyroid cancer had good outcomes, and in fact, may prevent unnecessary thyroid interventions. Therefore, the use of cervical ultrasound for parathyroid localization should be considered optional rather than essential.