Which of the following is not true regarding Medullary Ca thyroid?

Medullary thyroid cancer (MTC) originates from the parafollicular cells (C cells), which produce the hormone calcitonin. Approximately 25% of medullary thyroid cancer is genetic in nature, caused by a mutation in the RET proto-oncogene. When it coexists with tumors of the parathyroid gland and medullary component of the adrenal glands (pheochromocytoma) it is called multiple endocrine neoplasia type 2 (MEN2). The majority of C cells are located at the junction of the upper third and lower two thirds of the thyroid gland; hence, this is the most common location of MTC. On FNAC, MTC is characterized by the presence of stromal amyloid and the absence of thyroid follicles.