CALCA and medullary thyroid gland carcinoma: Thyroid malignomas (TM) are a heterogeneous group of neoplasm, which according to histopathological features are grouped in neoplasm originating from epithelial follicular cells, the differentiated thyroid carcinomas with the most frequent variants, papillary and follicular carcinoma and medullary thyroid carcinoma originating from neuroendocrine calcitonin-producing C-cells.