Medullary thyroid carcinoma (MTC) is a rare tumoral entity related to parafollicular C cells of the thyroid gland, characterized by peculiar morphological, functional and evolutional features. The aim of this study was to characterize the cases of medullary carcinoma diagnosed in a university hospital in a 5 years interval (January 1999December 2003) and to evaluate the diagnostic methods. In this time interval, from a total of 171 thyroid malignancy, 12 (7%) were medullary carcinoma. Most of the MTC (66.6%) presented clinical expression and high levels of calcitonin. In 1/3 the diagnosis was made by the morphological examination, which made necessary the immuno-histochemical confirmation. The morphological study included cytology of the samples of fine needle aspiration (FNAB), performed in all cases, extemporaneous examination and paraffine sections. Although FNAB could not establish the precise diagnosis, 11 of the 12 biopsies showed a malignant aspect. The immuno-histochemical reactions confirmed the diagnostic (positive for calcitonin and chromogranin A, negative for thyroglobulin). The MTC surgical treatment is aggressive, consisting in neck dissection with lymph-node dissection. Total thyroidectomy was performed in all cases, in 11 cases by first intention and in one case as a secondary step. All cases were in IIIrd tumoral stage. Only 2 cases in other series (mother and daughter) presented MEN type II. Time monitoring of the patients demonstrated secondary lymph node in 5 patients in a 312 months interval. All but one patient with associated pathology are still in life and have a good quality of life.
Conclusion: Clinical approach for medullary thyroid carcinoma, generally starting from a thyroid nodule, is based on pathological findings following fine needle aspiration biopsy. Calcitonin dosage and paraffin examination, completed with immuno-histochemistry are essential for the positive diagnostic. Early diagnosis and treatment are essential to improve life expectancy.
01 - 05 Apr 2006
European Society of Endocrinology