A 17-year-old boy was referred to our Department. In his medical history Crohns disease had been supposed because of abdominal pain and distention. He had previously undergone minor surgery as having large tongue with neuromas and hypertrophic gums. Due to his marfanoid appearance, arachnodactyly, massive eyebrows and lips together with his medical history, multiple endocrine neoplasia type 2B (MEN2B) was suspected, which is a very uncommon hereditary disease. It consists of typical dysmorphia, mucosal neuromas, ganglioneuromatosis, medullary thyroid carcinoma (MTC) and phaeocromocytoma, and the prognosis depends on the presence of MTC.
Two weeks later a 10-year-old girl presented with a hard mass at her neck. She had massive lips, neuromas on the tongue and solitary thyroid nodule. Thyroid scan showed a cold nodule in the right lobe, and fine needle aspiration cytology suggested MTC.
Genetic analysis was carried out in both patients and revealed a point mutation at codon 918 (M918T) of the proto-oncogene RET. Adrenomedullary function tests showed normal levels of serum and urinary fractionated catecholamines, however, high levels of plasma calcitonin related to MTC. Imaging studies did not identify metastases. Both patients underwent total thyroidectomy and lymph node dissection. Histological examination verified MTC in the thyroids and in the lymph nodes, too. After the operation the plasma calcitonin level of the girl decreased, but it remained high in the boy, so PET-CT was performed to look for metastases. These were found at his cervical region, therefore a reoperation was made with a more extensive node dissection. Since the operations (2006) both patients have been doing well.
Our conclusion is that whenever the M918T mutation of proto-oncogene RET is found total thyroidectomy should be done right after the diagnosis, or if possible within the first 6 months of life.