You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is All of the following are true about medullary carcinoma of thyroid except and explain in detail?
MEDULLARY CARCINOMA It is an uncommon type it arises from the parafollicular C cells which is derived from ultimobranchial body (neural crest) blood level of calcitonin is a tumour marker it is not dependant on TSH Most cases are sporadic and a small amount is familial ref ;(page no;486) 5th edition of SRB&;S Manual of SURGERY