Incidental detection of familial medullary thyroid carcinoma by calcitoninscreening for nodular thyroid disease

Serum calcitonin screening has recently been found to be a useful supplemen t to fine-needle aspiration biopsy, ultrasound and radionuclide imaging in the evaluation of thyroid nodules. We describe a case where introduction of routine calcitonin screening in nodular thyroid disease led to the detecti on of a family with medullary thyroid carcinoma. The benefits and problems of basal and stimulated serum calcitonin testing and ret-proto-oncogene mut ation studies are exemplified and we discuss the appropriate use and interp retation of these tests. We conclude that routine basal serum calcitonin me asurement in nodular thyroid disease and thoughtful use of ret-mutation ana lysis is cost-effective in detecting medullary thyroid carcinoma and multip le endocrine neoplasia type II.