This 12-year-old boy was tall and thin (height, 180 cm). He had lax joints and long extremities. School teachers had complained of his clumsiness and lack of coordination. Small submucosal nodules were present on his lips (Fig 1). He had chronic gastrointestinal symptoms with recurrent attacks of diarrhea for several years. A small nodule was felt in the left lobe of the thyroid gland, and thyroidectomy was performed (Fig 2 through 4). No other neck masses were palpable, and there was no significant enlargement of lymph nodes. A sister had died at age 14 years of a similar condition.
Diagnosis and Discussion
Medullary Thyroid Carcinoma in Multiple Endocrine Neoplasia Type IIB
The patient has continued to have high levels of serum calcitonin; however, 12 years after surgery, he is alive and asymptomatic.The familial form of medullary carcinoma of the thyroid becomes clinically apparent at a young age and is often multiple and bilateral. It is invariably accompanied by C-cell hyperplasia in the residual gland. Nearly all cases of medullary thyroid carcinomas occurring in children are of this type, which is characterized by autosomal dominant inheritance with complete penetrance. It frequently represents a component of multiple endocrine neoplasia type IIB. This type of neoplasia includes medullary thyroid carcinoma, pheochromocytoma, mucosal neuromata, intestinal ganglioneuromatosis, ataxia, marfanoid habitus, and skeletal deformities.1