Title: Multiple endocrine syndrome type 2B in early childhood
Abstract: Multiple endocrine neoplasia (MEN) 2B, a rare heritable syndrome of endocrine tumors secondary to activating mutations of the RET proto-oncogene, is associated with the early presentation of metastatic medullary thyroid carcinoma (MTC), an incurable disease once it spreads beyond the thyroid gland. The current standard of care in children who are identified as having MEN 2B is to remove all thyroid tissue prophylactically within the first year of life,1 but the unfortunate reality is that most MEN 2B patients are not recognized early enough because of the frequent de novo presentation of disease.2 The utility of prophylactic thyroidectomy in children with MEN 2A has been established,3 but little has been published about outcomes in MEN 2B patients. The journal Cancer previously published a report from our institution by Samaan and colleagues that highlighted the identification of an infant with MEN 2B and successful prophylactic thyroidectomy after a rise in pentagastrin-stimulated calcitonin levels.4 The patient presented as a neonate with failure to thrive, constipation, skeletal deformities, and rectal ganglioneuromas. The suspicion of MEN 2B was heightened by the detection of corneal nerve thickening at 3 months of life and a gradual increase in calcitonin with age instead of the anticipated natural decline. At around age 14 months, the patient had an uneventful prophylactic thyroidectomy with C-cell hyperplasia identified pathologically. We have been fortunate to see this patient in long-term follow up. She is now a 22-year-old student whose random calcitonin and carcinoembryonic antigen levels, both excellent markers of MTC, remain undetectable almost 21 years after prophylactic surgery. The clinical course of this patient adds to our growing understanding of the benefit of prophylactic thyroidectomy in MEN 2B and underscores the recommendation for early diagnosis and treatment of children with MEN 2B before the onset of metastatic MTC. Steven G. Waguespack MD*, Thereasa A. Rich MS, CGC , * Department of Endocrine Neoplasia and Hormonal Disorders, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.