ESPE Abstracts

Papillary thyroid cancer (PTC) is the most common thyroid tumor in childhood and adolescence. Most of these patients are referred with locally advanced and/or distant disease at the moment of diagnosis. Whenever is possible, these patients should be offered a total thyroidectomy and radioiodine remnant ablation. However, this approach is not always possible to perform, becoming these tumors as unresectable. These critical cases could benefit from the neoadjuvant treatment with multikinase inhibitors (MKI), so the standard treatment could be performed.

Lenvatinib is a MKI recently approved in many countries around the world for the treatment of radioiodine refractory adult differentiated thyroid cancer. Seldom pediatric case reports have been reported.

Case report: Female patient, 10 y.o. with a PTC locally advanced and metastatic to the lungs, who required 3 liters of oxygen due to the respiratory failure caused by the miliary bilateral pulmonary disease, mistakenly treated as tuberculosis two months previously to be referred to our Hospital.

A large thyroid mass fixed to profound tissues was corroborated with a CT scan, which showed a large heterogeneous neck mass with multiple microcalcifications associated to multiple lymph nodes. Both lungs had multiple micro-nodular disease with interstitial involvement.

Total thyroidectomy together with lymph node dissection was planned, but the extensive local infiltration led to define the unresectability of the lesion and the surgery was only limited to a thyroid biopsy. The patient had to undergo respiratory assistance. Pathological examination confirmed the presence of a PTC with a rearreangement of RET-PTC3 oncogene.

Eight days after surgery, we decided to indicate the compassionate use of Lenvatinib. Three days later, the patient had a clinical improvement and 9 days post Lenvatinib initiation the patient was discharged from hospital with no need of oxygen supply.

We are planning a new evaluation to define thyroidectomy and then radioiodine treatment.

Conclusion: Lenvatinib could be a very useful neoadjuvant therapeutic tool in pediatric patients with PTC not amenable for conventional treatment.