Rare Tumors: Part One.

Differentiated thyroid carcinoma (DTC) and melanoma are 2 rare cancers seen in pediatric patients. Both pediatric DTC and melanoma present with more advanced disease than their adult counterparts but also have improved long-term outcomes compared to adults. The primary treatment for DTC is surgery with compartment-based lymph node dissection in patients with clinically involved nodes. Wide local excision is the foundation of melanoma treatment, with sentinel lymph node biopsy and completion lymph node dissection based on disease characteristics. For both pediatric melanoma and thyroid carcinoma, molecular testing is an important component for diagnosis, risk stratification, and targeted therapies.