====== Medullary thyroid carcinoma ======
Medullary thyroid carcinoma (MTC) constitutes 5–10% of all [[thyroid carcinoma]]s and is the third most common type of thyroid cancer following papillary and follicular carcinomas.

It is derived from the parafollicular C cells and in this regard differs from the follicular cell-derived papillary and follicular carcinomas both clinically and pathologically.

MTC exhibits a more aggressive clinical behaviour and is more difficult to treat.

This is in contrast to papillary and follicular carcinomas, which respond to radioactive iodine and therefore may have a favourable clinical course, even in case of recurrence or metastasis.

MTC 1 cm in size is typically referred to as ‘micro-MTC’. Regional lymph nodes are the most common sites of metastasis for MTC. They are involved in 50% of cases at the time of presentation.

When distant metastasis occurs, the most frequently involved organs are liver, lung, bone and mediastinum.

===== Medullary thyroid carcinoma intracranial metastases =====

[[Medullary thyroid carcinoma intracranial metastases]]


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[[Hypercortisolism]] may also be due to ectopic secretion of [[ACTH]] usually by tumors, most commonly small-cell carcinoma of the lung, thymoma, carcinoid tumors, pheochromocytomas, and [[medullary thyroid carcinoma]].