Clinical characteristics, surgical approach, BRAFV600E mutation and sodium iodine symporter expression in pediatric patients with thyroid carcinoma.

Objectives Thyroid cancer is the most common endocrine neoplasm in childhood. There are few studies characterizing pediatric population in Colombia. We intend to detail the clinical, histological characteristics, BRAFV600E mutational status and NIS (sodium-iodine symporter) expression of children with papillary thyroid carcinoma (PTC) managed at Hospital de La Misericordia. Methods Medical records of the Department of Pediatric Surgery and Pathology from 2009 to 2018 were scrutinized in search of cases of differentiated thyroid carcinoma. A descriptive analysis was made. Paraffin embedded tumoral tissue was recovered to assess BRAF V600E mutational status by PCR and NIS expression by immunohistochemistry. Results Sixteen patients were selected, 81.2% were girls. Average age of presentation was 11.8 years. Only one patient had previous radiation exposure. Most frequent symptom was cervical adenopathy with a mean time of 29.2 weeks before diagnosis. 93.7% underwent total thyroidectomy and lymphadenectomy. 62.5% were PTC combining both classic and follicular pattern. 6.25% cases had BRAFV600E mutation and 25% showed NIS focal reactivity. Conclusions We found greater female predominance, lower percentage of risk factors described and a high percentage of patients requiring aggressive surgical treatment. We consider important to contemplate thyroid cancer as a differential diagnosis of cervical lymph node enlargement in children. Diagnosis can be challenging in benign and indeterminate categories of the FNA cytology and biomolecular profiles such as BRAF and NIS could be determinant in guiding treatment. More studies with larger sample size, complete genetic analysis, evaluation to iodine response and long term follow up are required.