Background and aims Patients affected by metastatic germ cell tumors may occasionally experience enlargement of metastatic lesions with concurrent normalization of tumor markers after chemotherapy. This phenomenon is described as Growing Teratoma Syndrome (GTS). The aim of the present study is to assess the prevalence of GTS in the pediatric population and its implications in terms of surgical outcome. Methods The clinical notes of patients diagnosed with stage III and IV malignant germ cell tumors from January 2010 until December 2020 at our Institution were retrospectively reviewed. Patients with residual disease after chemotherapy were studied; the occurrence of GTS, treatment strategies, survival and outcome were analyzed. Results Thirty-three patients with high stage malignant germ cell tumors were diagnosed in our Institution in the analyzed period. Eleven patients (34%) had radiologic evidence of enlargement of metastases after chemotherapy; nine of them (28%) had normal markers after chemotherapy and were classified as GTS patients. All nine patients underwent resection of metastatic lymph nodes and six had surgery on visceral metastases. In six patients, radical excision of all metastatic sites was achieved; five patients are alive and in complete remission while one died for peri-operative complications. Out of the three patients who could not achieve radical excision of the metastases, two died for progressive disease and one is alive with progressive disease. Conclusions Patients affected by GTS have a risk of progression of chemotherapy-resistant disease and death. Radical surgical excision is essential to achieve disease control and long-term survival.

Background: Thyroid gland malignancy is rare in pediatrics (0.7% of tumors); only 1.8% are observed in patients < 20 yrs with a higher prevalence recorded in females and adolescents. Risk factors include genetic syndromes - MEN disorders, autoimmune disease and ionizing radiation exposure. Radiotherapy is also linked with increased risk of secondary thyroid cancers. The present study describes the clinical features and surgical outcomes of primary and secondary thyroid tumors. Methods: Institutional data was collected on pediatric patients with thyroid cancer during 2000 - 2020 from 8 International Surgical Oncology centers. Statistical analysis was performed using GraphPad Prism. Results: Of 255 cases of thyroid cancer, only 13 (5.1%) were secondary tumors. Primary thyroid malignancies were more likely to be multifocal in origin (odds ratio [OR] 1.993, 95% confidence interval [CI] 0.7466-5.132, p 0.2323), had bilateral glandular location (OR 2.847, 95% CI 0.6835-12.68, p 0.2648) and proved metastatic at 1st diagnosis (OR 1.259, 95% CI 0.3267-5.696 p>0.999). Secondary tumors showed a higher incidence of disease relapse (OR 1.556, 95% CI 0.4579-5.57, p 0.4525) and surgical morbidity (OR 2.042, 95% CI 0.7917-5.221, p 0.1614) including hypoparathyroidism and recurrent laryngeal nerve injury. Overall survival (OS) was 99% at 1 year and 97% after 10 years. No EFS differences were evident with primary vs. secondary tumors (Chi square 0.7307, p 0.39026). Conclusions: This multicenter study demonstrates excellent survival for pediatric thyroid malignancy. Secondary tumors exhibit greater disease relapse (15.8% vs 10.5%) and a higher incidence of surgical related complications (36.8% vs 22.2%).

Lung cancer is the leading cause of cancer-related death. NSCLC accounts for 80-90% of cases. In younger patients, adenocarcinoma is the most frequent histotype and 3-7% expresses the rearrange-ment of ALK oncogene, sensitive to TKIs. Crizotinib is the first ALK inhibitor approved by FDA. We present the case of a 17-year-old male with metastatic naïve ALK-positive adenocarcinoma, treated with crizotinib. He received crizotinib and obtained a prolonged response with PFS of 33 months. Crizotinib can be extremely effective in adolescent with naïve ALK-positive NSCLC but it hardly penetrates blood-brain barrier. Resistance mechanisms will be investigated for a better man-agement.