<prompt> Calcitonin is a marker of -Prostate cancerMedullary carcinoma of thyroidPheochromocytomaPancreatic cancer  <response>: Harshmohan textbook of pathology 7th edition. medulla carcinoma is a less frequent type derived from para follicular or C cells present in the thyroid. Like normal C cells tumor cells of medullary carcinoma secrete calcitonin the hypo calcimic hormone. So calcitonin is an impoant tumor marker of medullary carcinoma of thyroid. . 