Disease Burden and Outcome in Children and Young Adults With Concurrent Graves Disease and Differentiated Thyroid Carcinoma.

Context: Adults with differentiated thyroid cancer (DTC) and Graves disease (GD) demonstrate a greater reported disease burden and aggressive DTC behavior. To date, no studies have examined the impact and long-term outcome of concurrent GD and DTC (GD-DTC) in children and young adults. Design: Single institution, retrospective longitudinal cohort study between 1997 and 2016. Participants: One hundred thirty-nine children and young adults with DTC, diagnosed at median age 15 (range, 5 to 23) years, compared with 12 patients with GD-DTC, median age 18 (range, 12 to 20) years. Major Outcome Measures: Patient demographics, preoperative imaging, fine needle aspiration (FNA) cytology, operative and pathological reports, laboratory studies, treatment, and subsequent 2-year outcomes. Results: Compared with DTC, patients with GD-DTC were significantly older at the time of DTC diagnosis (P < 0.01). Patients with GD-DTC were more likely to exhibit microcarcinoma (P < 0.01), and 2 of 12 (17%) demonstrated tall cell variant papillary thyroid cancer (PTC) vs 2 of 139 (2%) in patients who had DTC alone (P = 0.03). Although patients with DTC showed greater lymphovascular invasion (60% vs 25%; P = 0.03), no group differences were noted in extrathyroidal extension, regional lymph node, and distant or lung metastasis. There were no group differences in the 2-year outcome for remission, persistent disease, or recurrence. Conclusions: Concurrent DTC in pediatric patients with GD is not associated with a greater disease burden at presentation and shows no significant difference in 2-year outcomes compared with DTC alone. Similar to adults, microcarcinoma and tall cell variant PTC is prevalent in pediatric patients with GD-DTC. For patients who have GD-DTC with an identified nodule on ultrasound imaging prior to definitive therapy, FNA biopsy is recommended to guide definitive treatment.