Flashcards in Thyroid Cancer Deck (25)
What can be concluded if a thyroid nodule is found?
Most tend to be benign so a diagnosis requires more examination.
What can you do when you find a thyroid nodule?
Radioactive Iodine (I 131) uptake study, if increased uptake then indicative of graves or nodular goiter. If decreased uptake then adenoma and carcinoma.
If thyroid adenoma or carcinoma is suspected what test must be done?
FNA, fine needle biopsy, because biopsy of the thyroid is going to cause excessive bleeding due to extensive vascularaization of the thyroid.
What are the 4 main kinds of Thyroid Carcinomas? List them from most common to least.
Papillary, Follicular, Medullary ,Anaplastic
What is a "Follicular Adenoma?"
Benign proliferation of FOLLICLES surrounded by a fibrous capsule, usually non functional and rarely secretes anything.
** Note, follicular carcinoma is the above but in addition the follicular cell breaches t he fibrous capsule and extends into the adjoining tissues.
What is a major risk factor for papillary carcinoma?
Ionizing radiation exposure during childhood, in things like extreme acne tx.
What is the ABSOLUTE diagnosis of papillary carcinoma?
Microscopic confirmation of the nuclear features, specifically the "Orphan Anne Eyed" nuclei, as well as nuclear grooves and psamomma bodies.
What are "Orphan Anne Eyed" nuclei?
Seen in pappillary carcinoma, the nucleus is somewhat opaque.
Where does papillary carcinoma of the thyroid spread to?
Cervical lymph nodes of the neck, however prognosis is good regardless.
What defines a follicular carcinoma?
Malignant proliferation of follicular cells, similar to folliccular adenoma in that a fibrous capsule surrounds the tumor however the carcinoma variant will breach the capsule.
Can we use FNA to distinguish follicular carcinoma from adenoma?
No, because to do that we would actually need to see the capsule and see if the tumor breaches the capsule, the FNA will just show the follicular cells.
What is the metastasis pattern of follicular carcinoma?
Rather than lymph spread, it loves to go hemotogenously, one of 4 cancers known to do this.
What are the 4 cancers known to spread hematogenously rather than through lymph in terms of metastasis?
Renal cell carcinoma (Renal vein to blood), follicular carcinoma, Hepatocellular carcinoma (Hepatic vein to blood), and Choriocarcinoma quickly spreads to the blood.
What is a "medullary carcinoma?"
Malignant proliferation of the parafollicular C cells (which make calcitonin). Associated with high levels of calcitonin.
What is the function of calcitonin?
Secreted by C cells, its function is to lower the blood levels of calcium by inducing renal excretion of calcium.
How does medullary carcinoma mess with the body's reserve of calcium?
Can induce hypocalcemia due to effects of calcitonin, and can also deposit calcium into the tumor as "Amyloid."
Who are more prone to get thyroid cancer?
Women are about 3x more likely than men.
What is the buzzword for Medullary carcinoma?
Malignant cells in an amyloid stroma on a FNA.
What is the inciting agents for the familial cases of Medullary carcinoma of thyroid?
Due to MEN 2A and 2B (Multiple Endocrine Neoplasia). This is associated with mutations a mutation in the RET oncogene.
What happens if there is a family history of medullary carcinoma and a RET oncogene mutation is detected?
What are the 3 cancers induced by the MEN 2A? 2B?
Medullary carcinoma of the thyroid (also 2B does this), Pheochromocytoma (also 2b), and parathyroid adenomas. 2B has the same thing but rather than parathyroid adenomas you get ganglion cytomas of oral mucosa.
Family predisposition to medullary carcinoma is associated with?
RET oncogene mutations.
What is anaplastic carcinoma?
Undifferentiated malignant tumor of the thyroid. Usually seen in the elderly although a similar clinical presentation is seen in younger females (Rydel's Fibrosing thyroiditis).
Where does anaplastic carcinoma spread to? Prognosis?
Often spreads to local structures leading to dysphagia or respiratory comprimise. Very poor prognosis.