5% of malignant thyroid neoplasms
Peak incidence in the fifth to sixth decades of life
Sings may include dysphagia, hoarsness, cough, or diarrhea. The familial cases are normally discovered by routine screening of the serum of the patient for the elevated level of calcitonin.
Discrete tumors in one lobe of the thyroid gland (sporadic cases) or multiple nodules in both lobes of the thyroid gland (the familial form).
Consists of the parafollicular neuroendocrine C cells in the thyroid gland.
Consists of spindle or polygonal cells.
Cells are arranged in sheets and trabeculae.
Within the stroma, amyloid deposits may be seen.These deposits are likely to be derived from calcitonin secreted by the tumor cells.