DOI: https://doi.org/10.36347/sjmcr.2025.v13i10.023

Pages: 2284-2288

Medullary thyroid carcinoma (MTC) is an uncommon thyroid malignancy in the pediatric population, accounting for a small proportion of thyroid cancers in children. We report the case of a 13-year-old boy who presented with progressive respiratory symptoms and was ultimately diagnosed with sporadic MTC with pulmonary metastases. Initial imaging suggested a compressive thyroiditis, but worsening symptoms led to emergency total thyroidectomy, tracheostomy, and lymph node dissection. Histopathological examination cofirmed MTC with extracapsular spread and lymph node involvement. Interestingly, the child exhibited thickened lips, raising suspicion of a dysmorphic syndrome. Genetic testing for RET mutations, including exon 11, returned negative, supporting a sporadic form of the disease. The patient was started on selpercatinib (40 mg twice daily) and levothyroxine (125 μg per day), with clinical stability observed over the subsequent six months. This case highlights the importance of early diagnosis and comprehensive management of pediatric MTC, especially in cases with atypical features.