Disease Burden and Outcome in Pediatric and Young Adults with Concurrent Graves Disease and Differentiated Thyroid Carcinoma.

Context: Adults with differentiated thyroid carcinoma (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 pediatric and young adults.

Design: Single institution, retrospective longitudinal cohort study between 1997-2016.

Participants: 139 pediatric and young adults with DTC, diagnosed at median age 15 (range 5-23) years compared to 12 GD-DTC patients, median age 18 (range 12-20) years.

Major Outcome Measures: Patient demographics, pre-operative imaging, fine needle aspiration (FNA) cytology, operative and pathological reports, laboratory studies, treatment, and subsequent 2-year outcomes.

Results: Compared to DTC, GD-DTC were significantly older at the time of DTC diagnosis (p<0.01). GD-DTC were more likely to exhibit micro-carcinoma (p<0.01) and 2/12 (17%) demonstrated tall-cell variant PTC vs 2/139 (2%) in DTC alone (p=0.03). While DTC patients showed greater lymphovascular invasion (60% vs 25%; p=0.03), no group differences were noted in extra-thyroidal extension, regional lymph node, 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 GD patients is not associated with a greater disease burden at presentation and shows no significant difference in 2-year outcomes compared to DTC alone. Similar to adults, micro-carcinoma and tall-cell variant PTC is prevalent in pediatric GD-DTC. For GD-DTC patients with an identified nodule on ultrasound imaging prior to definitive therapy, FNA biopsy is recommended to guide definitive treatment.