Thyroid nodules occur rarely in children but frequently raise the possibility of carcinoma. Because of the higher risk for malignancy, there tends to be a more aggressive approach towards biopsy and resection. Hot nodules are usually benign but not always, and FNA can be difficult or impossible in some children. Therefore, there is a very low threshold for recommending biopsy in the form of thyroid lobectomy. Although no imaging study is 100% accurate, ultrasound has become invaluable in the assessment of the thyroid gland and the lymph nodes of the neck, with some experienced ultrasonographers able to distinguish benign nodules and lymph nodes from malignant ones. In rare cases, a needle-core biopsy can be done for palpable lesions or with ultrasound guidance under general anesthesia. Bleeding is a risk but gentle pressure along the biopsy tract is an effective tamponade.
If the nodule is proven to represent malignancy, total thyroidectomy is usually recommended, even for small papillary carcinomas. This protects the patient from bilateral disease, allows more effective treatment of metastases with 131I ablative therapy, permits the use of thyroglobulin as a marker for recurrence, and increases the sensitivity of postoperative scans. In experienced hands, the risk of recurrent laryngeal nerve injury or hypoparathyroidism after total thyroidectomy should be quite low. In the end, regarding the question of total vs. subtotal thyroidectomy, the surgeon must make the decision that is safest for the child in the context of the resources available at their institution, the preferences of the endocrinologists who will be following the child after the operation, and his or her own experience and skill set. In some situations, this should prompt the family to be referred to a tertiary care center or other institution with more experience and a safe track record.
The surgical technique for thyroidectomy is essentially the same as it is in adults. The cleaner planes of the child’s neck allow the surgeon to maintain a plane of dissection essentially right on the capsule of the thyroid throughout the operation. The recurrent laryngeal nerve is usually easily identified and is frequently much larger than expected given the size of the child. Recurrent laryngeal nerve monitoring should be considered standard of care for reoperative surgery, for children with pre-existing unilateral vocal cord paralysis, and when the tumor is infiltrative or invasive; however, for primary operations in healthy children with nonaggressive tumors it is optional. The parathyroid glands can be difficult to identify in children but every attempt should be made to do so. A tiny piece of any questionable tissue should be sent for biopsy and, if it appears to be ischemic, should be placed on ice until the frozen-section diagnosis is returned. If confirmed to be parathyroid tissue, it should be implanted into the sternocleidomastoid muscle. It is also extremely important to perform a proper lymph node dissection when dealing with any carcinoma, but especially medullary cancer. The surgeon should be familiar with all the anatomic zones of the neck including their borders and their contents and the details of the operation should be recorded with precision for staging purposes. For metastatic papillary carcinoma, removing all clinically positive nodes is usually sufficient and second or third operations to remove newly positive nodes is not unheard of. Even in the presence of metastases, papillary thyroid carcinoma is associated with an extremely good prognosis.
Parathyroid adenomas are rare but there should be an earnest attempt to localize it preoperatively with ultrasound, sestamibi scan or even MRI of the neck. Surgical treatment of four-gland hyperplasia is somewhat controversial, but given the dynamic nature of a child’s metabolism and unpredictable changes in endocrine status with growth and development, it seems prudent to remove all glands and place a portion in the muscle of the forearm while preserving some extra tissue properly frozen in the event more is needed in the future. To have to return to the neck for a second operation seems unnecessarily risky.