Medullary Thyroid Carcinoma

This chapter provides an overview of the diagnosis and treatment of medullary thyroid carcinoma in young patients. Advances in the molecular diagnosis of multiple endocrine neoplasia type 2 have made it possible to diagnose this disorder with certainty in most patients during early childhood. This diagnostic capability is likely to lead to improved clinical outcomes, but it also raises a series of questions and concerns related to surgical intervention in a child. Each of these complex issues is addressed. Medullary thyroid carcinoma is a malignant neoplasm that is characterized primarily by its production of calcitonin and carcinoembryonic antigen (CEA). Calcitonin is a small peptide originally identified by its ability to lower the serum calcium concentration. The finding of calcitonin and CEA in a tumor with neuroendocrine features is almost always predictive of medullary thyroid carcinoma, and the finding of amyloid is confirmative. There are 2 subtypes of medullary thyroid carcinoma: sporadic and hereditary. The hereditary form is the most common subtype in the pediatric population.