The document discusses medullary carcinoma of the thyroid gland. It begins with an overview of thyroid anatomy and the characteristics of medullary thyroid carcinoma, which originates from C cells that produce calcitonin hormone. The document then examines the causes, types, risk factors, signs and symptoms, diagnostic tests, treatment options including surgery, radiotherapy and chemotherapy, and prognosis for medullary thyroid carcinoma. It also references several medical studies and articles on topics such as variants of medullary thyroid carcinoma and detection of metastases.