Now, we’ve talked about the multiple endocrine neoplasia type 1 in other lecture series.
Let’s visit a multiple endocrine neoplasia type 2. Type 2 specifically involves a pheochromocytoma.
Again, it’s important to note most pheochromocytomas are actually sporadic and not
part of syndromes. So, type 2a includes a pheochromocytoma, medullary thyroid cancer.
Do you remember what specific tumor marker is associated with medullary thyroid cancer?
I’ll tell you in a second; and parathyroid hormone. That’s right. Medullary thyroid cancer
is associated with the RET proto-oncogene. Go back to the thyroid lectures if you need to review.
Now, let’s visit multiple endocrine neoplasia type 2b. Similar to 2a, it also includes
pheochromocytoma, medullary thyroid cancer, and in this instance, mucocutaneous neuromas.
These are important concepts for multiple endocrine neoplasias and you should commit
these to memory. What constitutes a malignancy? Unlike many other cancers
that you’ve reviewed, 10% are malignant and more common to be malignant if the paraganglioma
is extra adrenal. Remember the rules of ten? Think about what the rules of ten are for
the adrenal gland. Malignancy in terms of adrenal tumors equals metastases.
Therefore, if it’s localized then there’s no metastasis and it’s unlikely to be malignant.
What are some of the signs that malignancy occurs: bone, liver, and lymph nodes.
It should be part of your metastatic workup. Remember, since most of these patients
obtain preoperative imaging, many of the metastases will show up.