MON-328 Invasive Papillary Thyroid Carcinoma With Lymph Node and Tracheal Involvement: A Case Report and Treatment Approach

Abstract Disclosure: M. Aboumourad: None. M. Kashat: None. P. Choobchian: None. F.R. Shaya: None. J. Hotaling: None. C. Gonzalo: None. Background: Papillary thyroid carcinoma (PTC) or differentiated thyroid carcinoma (DTC) carry an excellent prognosis with high survival rates and low recurrence. The standard treatment for locally advanced DTC is surgery, at times followed by radioactive iodine therapy. In recurrent or metastatic disease that is refractory to radioactive iodine, the 10-year survival rate is 15-20%. Factors such as age, sex, tumor size, lymph node involvement, and extrathyroidal extension impact recurrence and mortality. Tracheal invasion in PTC is observed in 0.5-1.5% of cases. This case demonstrates the treatment approach using neoadjuvant tyrosine kinase inhibitors (TKI) therapy to reduce tumor size, facilitating a less morbid surgery. Clinical Case: A 72 year-old female presented with progressive three month history of dyspnea with massive hemoptysis. CT chest revealed a 3.1 x 2.5 cm right thyroid lobe mass with subglottic tracheal invasion causing significant narrowing with two suspicious left retroclavicular lymph nodes. Due to mass effect and persistent bleeding, the patient underwent emergent tracheostomy, open biopsy, and lymph node resection, which revealed PTC with metastasis. Concurrent bronchoscopy, with biopsy of the tracheal mass demonstrated PTC. The patient was started on lenvatinib to reduce tumor size, creating the best conditions for the planned total thyroidectomy. Conclusion: The use of anti-angiogenic, multi-targeted TKIs, particularly lenvatinib, as a preoperative treatment to reduce tumor burden is promising in managing metastatic and recurrent, radioactive iodine-refractory DTC. Lenvatinib directly inhibits key receptors involved in tumor progression, including vascular endothelial growth factor receptors, fibroblast growth factor receptors 1-4, platelet-derived growth factor receptor-alpha, and the RET and KIT proto-oncogenes. While neoadjunctive TKIs are overall effective, common side effects include diarrhea, decreased appetite, hypertension, dermatitis, neuropathy, bleeding and, in severe cases, fistula formation, mucosal perforation, and cardiotoxicity including TKI-induced cardiomyopathy. Neoadjuvant TKI therapy poses potential for surgical cure, and may reduce the need of aggressive resections, such as laryngectomy, tracheal resection, and esophagectomy. This case highlights the emerging role of incorporating neoadjunctive TKI therapies in the management of newly diagnosed locally aggressive PTC to improve surgical outcomes and overall patient prognosis. Presentation: Monday, July 14, 2025