Normal thyroid pathology in patients undergoing thyroidectomy for finding a RETgene germline mutation: A report of three cases and review of the literature

Genetic screening for germline RET proto-oncogene mutation in hereditary me dullary thyroid cancer (MTC) is accurate and allows for preventive total th yroidectomy to be performed early in patients who are gene carriers. We rep ort 3 children who underwent preventive total thyroidectomy based on the fi nding of a RETgene germline mutation, but who had no evidence of MTC or C-c ell hyperplasia on permanent histology, even after calcitonin immunostainin g. Review of the English literature of patients undergoing preventive thyro idectomy for a positive RETgene germline mutation, shows that 3.4% of these patients (a total of 209 patients) had normal thyroid glands. Also, 8.6% o f patients undergoing preventive total thyroidectomy with prophylactic cent ral neck node dissection had cervical node metastases. We conclude that pre ventive thyroidectomy in patients screened early for germline RETgene mutat ion allows for earlier diagnosis and treatment of patients, sometimes even before any hyperplasia or neoplasia can be demonstrated because cervical no de metastases can occur early and be demonstrated even with small tumors (< 1 cm), we recommend prophylactic central neck node dissection at the time of preventive thyroidectomy.