Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant condition that is rare in childhood. MEN2 is sub-classified into three categories that all include familial medullary thyroid carcinoma (MTC). Familial MTC has no other associated tumours. MEN2A is characterised by MTC, phaeochromocytoma and parathyroid tumours and MEN2B consists of MTC, phaeochromocytoma, ganglioneuromatosis and usually a Marfanoid habitus. The identification of RET as the causative gene has allowed early diagnosis of such conditions in asymptomatic children of adult patients. The natural history of MTC varies according to the mutation. Patients with certain genetic mutations commonly develop MTCs in childhood, meaning that screening has become a key focus of clinical management. We will describe the clinical surveillance protocols undertaken at our centre which are used during childhood.
We will look at the use of prophylactic thyroidectomy in the management of these cases, as well as the role of the Pentagastrin test for screening. To illustrate this, we describe the management of two children, one with MEN2B and one with possible MEN2A/familial MTC. Patient 1 is a 15 yr old girl who was diagnosed with a mutation in the RET gene known to cause MEN2B. She subsequently underwent a total thyroidectomy. Patient 2 is a 12 yr old boy with a paternal history of MTC. No known RET gene mutation has yet been identified in this family and he continues to undergo MTC screening with annual Pentagastrin stimulation testing.