Endocrine Abstracts

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor derived from the thyroid C cells producing calcitonin, ac-counts for 0.6% of all thyroid cancers. It occurs either sporadically or in a hereditary form (RET mutation). MTC can be cured only by complete resection of the thyroid tumor and any loco-regional metastases. Calcitonin (CT) measurement is crucial to the early diagnosis and the follow-up of MTC. If the evaluation of stimulated CT levels is required, a provocative test can be performed. We report the case of a 52-year-old woman presenting with multinodular goiter, positive TPO antibody and basal CT in repeated samples 42.92, 38.15, and 33.99 pg/ml respectively. The patient was euthyroid. Plasmatic metanephrines and PTH were in normal ranges. The thyroid ultrasound showed an isoechoic nodule 6 mm in size with a punctate calcification in the left lobe and two hypoechoic nodes on the right lobe 19 and 9 mm in size, with central and peripheral vascular signal. After a provocative test with high dose Ca was performed, stimulated CT level was 96.6, 98.10 and 82.10 pg/ml at 2, 5 and 10 min respectively. The patient underwent total thyroidectomy. The histology showed multifocal medullary microcarcinoma (max 5/5 mm in the left lobe), pTN: pT1a(m) Nx and positive immunohistochemistry for calcitonin. Postoperatively calcitonin level <0.2 pg/ml and CEA was negative. The mutations of RET protooncogene was tested, too.

Conclusion: We have to pay attention for patients with bCT >10 pg/ml and, a high-dose Ca test is reliable for the identification of MTC.