Interest of Routine Measurement of Serum Calcitonin: Study in a Large Series of Thyroidectomized Patients

Abstract

The aim of our study was to assess the ability of routine calcitonin (CT) measurement to improve the preoperative diagnosis of medul- lary thyroid carcinoma (MTC) in nodular thyroid diseases. We sys- tematically determined basal CT in 1167 patients before thyroid sur- gery and performed a pentagastrin (Pg) CT stimulation test in 121 of these patients whose basal CT level was normal. Sixteen MTC (1.37%) were found on histopathological examination of surgical specimens: 14 in the 34 patients (41.1%) with abnormal basal CT levels and 2 in the 1133 patients with normal basal CT levels (0.17%). An abnormal increase in Pg-stimulated CT was observed in 7 of the 121 patients tested and was related to microscopic MTC in 2 cases. Among 1167 thyroidectomized patients with nodular thyroid dis- eases, the prevalence of MTC was 1.37% and reached 41.1% when the basal CT level was abnormal (3% of the patients). CT evaluation detected MTC, whereas other procedures, such as fine needle aspi- ration cytology, failed, thus allowing early radical surgery. CT measurement should thus become a routine part of the diag- nostic evaluation of nodular thyroid diseases. (J Clin Endocrinol Metab 82: 338 -341, 1997)