Pediatric Thyroid Disorders: Update Course 2016

There is a documented increase in pediatric thyroid disease over two decades based on SEER database analysis, including large thyroid nodules not attributable to better screening alone.

Approximately 4-5% of children have thyroid nodules, and of those, roughly 30% are malignant, which is an inverse ratio compared to adults where nodules are more prevalent but malignancy rates are lower.

In pediatric populations, thyroid cancers tend to have more nodal disease, are more multifocal, and are more likely to be metastatic to lung or bone compared to adult populations.

Predictors of malignancy in pediatric thyroid nodules include male gender, compression symptoms, palpable lymphadenopathy, higher TSH levels, microcalcifications, indistinct margins, hypochoic pattern, and increased nodular vascularization on ultrasound.

The incidence of differentiated thyroid cancer in hyperfunctioning nodules is upwards of 10 times higher in children than in adults, leading to general recommendations to remove hyperfunctioning nodules in pediatric patients.

In 10-40 year follow-ups of pediatric thyroid cancer, 98% overall survival is achieved, but of the deaths that occur, two-thirds are from non-thyroid malignancies, and most of those patients had received radiation treatment.

A Washington group analyzing the National Cancer Database found no difference in 15-20 year outcomes between partial thyroidectomy (ipsilateral thyroidectomy and isthmectomy) and total thyroidectomy for nodules over 1 centimeter, suggesting total thyroidectomy may not be necessary for all papillary thyroid cancers.

National Inpatient Sample data on 16,000 adult patients over 10 years shows surgeons performing fewer than 25 thyroidectomies per year have approximately 90% higher risk of overall complications compared to high-volume surgeons.

Pediatric-specific National Inpatient Sample data shows low-volume surgeons (1-2 cases per year) have nearly twofold higher rates of inpatient complications compared to high-volume surgeons.

Only 5% of pediatric surgeons performing thyroid surgery in the National Inpatient Sample qualified as high-volume surgeons, meaning most pediatric surgeons doing thyroid surgery are low-volume surgeons.

Overall rate of hypoparathyroidism after partial or total thyroidectomy is 5-15%, with most cases being transient. Low-volume surgeons have approximately 2.5% permanent hypoparathyroidism rate, representing nearly a fivefold higher rate than high-volume surgeons.

Central node dissection significantly increases rates of both recurrent laryngeal nerve palsy and hypocalcemia (transient or permanent) compared to thyroidectomy without node dissection.

Risk factors for recurrent laryngeal nerve injury include large tumor, non-visualized nerve, malignancy, nodal dissection, and redo operations.

Overall statistics show approximately 0.3-1% risk of permanent recurrent laryngeal nerve injury and 1-6% risk of transient palsy in pediatric thyroidectomy patients.

Approximately 15% of children presenting with thyroid cancer already have nerve dysfunction at baseline, making preoperative laryngoscopy valuable for documentation.

The 2016 American Thyroid Association guidelines state that ultrasound characteristics of thyroid nodules are important beyond size alone, and fine needle aspiration must be done under ultrasound guidance rather than by palpation.

There is insufficient evidence in pediatrics to suggest that specific cancer genetic characteristics can predict outcomes or determine which patients should receive certain treatments.

Surgical resection is recommended for any hyperfunctioning nodule in children. Controlling hyperthyroidism is important for operative safety but does not eliminate the need for nodule removal, which typically means lobectomy.

Radioactive iodine ablation is not recommended across the board for low-risk pediatric thyroid cancer patients (those with disease confined to the thyroid or only incidentally found in surrounding lymph nodes), representing a significant change from adult practice.

The American Thyroid Association guidelines state that children with differentiated thyroid cancer should be taken care of at a center of excellence.

Thyroid tumor boards that include nuclear medicine, surgery, endocrinology, pathology, and oncology produce dramatically different and more nuanced treatment discussions than email communication, particularly for complex cases involving rising thyroglobulin levels and decisions about re-ablation versus re-exploration.

Dave Wesson presented data at ABPSA showing that double-scrubbing (two attendings operating together) in a smaller-volume thyroid surgery practice resulted in very low complication rates and drew patients back into the Texas Children's Hospital system from the community.

Aggressive parathyroid reimplantation has dramatically dropped hypoparathyroidism rates. The approach is to assess parathyroid glands intraoperatively: if they look dusky, cut them to check for red blood; if there is red blood, leave them in place; if not, remove and reimplant them. Reimplanted glands take about one month to return to function.

Intraoperative parathyroid hormone (iPTH) is measured in the recovery room and again at 6 and 8 hours postoperatively. If iPTH is less than 10, patients are started on vitamin D and calcium. If iPTH is in the 30s, patients are supported expectantly as function is expected to improve.

Thyroid surgery is a profession that has changed more than almost any other in the last 10 years, with thyroid guidelines being rewritten four times in that period.

Anyone performing thyroid surgery must read the pediatric thyroid surgery guideline to ensure compliance, as these guidelines are developed by experts who specialize in this area. Surgeons doing one-off cases once or twice a year are not providing the quality of care that defines pediatric surgery in other areas.

Pediatric surgery has completely changed in the last 15-20 years, with the specialty increasingly focused on abscesses and appendectomies while fine cases are lessening. This trend suggests increasing benefit from having two attendings operate together to maintain adequate case volumes.