Persistent hypercalcitoninemia in patients with medullary thyroid cancer: A therapeutic approach based on selective venous sampling for calcitonin

Background. Persistent or recurrent medullary thyroid carcinoma (MTC) can b e cured by microdissection of residual metastatic lymph nodes in the neck. Selective venous sampling can be used for localization. The aim of this stu dy is to prospectively analyze our results with a therapeutic approach base d on venous sampling, in patients with hyperthyrocalcitoninemia after thyro idectomy for MTC. Methods. Selective venous sampling for determination of s timulated calcitonin was obtained in all patients after performing a comple te laboratory and imaging workup. Patients with a gradient between the supr ahepatic vein and the superior vena cava underwent unilateral or bilateral extensive lymph node dissection. We used the gradient between the right and left jugular veins to decide which side of the neck to operate. Calcitonin levels were obtained after surgery and a pentagastrin test was performed o ne year later if basal levels remained normal. Results. Mean age of the fiv e women with a neck gradient in the selective venous sampling who underwent neck exploration was 45 years. In all patients metastatic lymph nodes were found at the site suggested by the study. Mean positive/resected lymph nod es were 5/20. Postoperative basal and stimulated levels of calcitonin becam e normal in two patients at one year of follow up, Conclusion. Selective ve nous sampling is useful to localize recurrent MTC.