All of the following are true about medullary carcinoma of thyroid except
It is tumour arising from C cells derived from the neural crest
Secrete high levels of calcitonin
It is not dependent on TSH
Most cases are familial
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
Endocrinology and breast