Primer 7 - Hypothyrodism and Thyroid Cancer Flashcards
What are five causes of cretinism?
- Iodine-deficient diet
- Thyroid-related enzyme deficiency
- Thyroid developmental defect
- Failure of thyroid descent during development
- Transfer of antithyroid antibodies from the mother with an autoimmune disease to the fetus.
What is the most common cause of hypothyroidism in the US?
Hashimoto Thyroiditis.
What do we find in the physical exploration of Hashimoto Thyroiditis?
Hypothyroidism with painless goiter, dense infiltrate of lymphocytes into the thyroid.
Which HLA genes are associated with Hashimoto Thyroiditis?
HLA-DR5
HLA-B5
How do we diagnose Hashimoto Thyroiditis?
- Antithyroglobulin
- Antithyroid peroxidase antibodies
How come people with Hashimoto Thyroiditis may have a short period of hyperthyroidism in the early phase of the disease?
As the inflammation begins, it causes destruction of follicle cells, and spilling of T3 and T4.
Which type of lymphoma are Hashimoto patients are vulnerable to?
B cell lymphoma.
What is another name for Subacute thyroiditis?
de Quervain.
What is the progression of Subacute thyroiditis?
- Early stages can be seen with hyperthyroidism due to inflammation of follicle glands that spill T3 and T4. Later transitions to hypothyroidism
What is the classic clinical presentation of subacute thyroiditis?
Hypothyroidism with painful goiter.
Which HLA gene is subacute goiter related?
HLA-B35
What is suspected to be the cause of subacute thyroiditis?
Post-viral disease, like measles, mumps, coxackie, echo virus, etc.
What is Riedel’s thyroiditis and what do we find in physical exploration?
Chronic inflammation of thyroid that leads to fibrous tissue. We find in physical exploration that they thyroid is fixed, hard rock-like thyroid. It is painless.
What is the clinical presentation of Riedel’s thyroiditis? What do we see in histological finding?
Hypothyroid or euthyroid. Histology: Lots of fibrosis but we can find macrophages and eosinophils.
What type of thyroiditis has lymphocytic infiltration on the thyroid?
Hashimoto.
If we have an increase in radioactive iodine uptake in the thyroid, the type of cancers that can be suspected to have are:
Grave’s diases, mutlinodular, or single toxic adenoma.
What is the most common type of thyroid cancer?
Papillary tumor.
Which type of thyroid cancer has the best prognosis?
Papillary cancer.
What do we see in the histological findings of papillary tumor of the thyroid?
Ground-glass appearance of nuclei : “Orphan Annie eye”. Also, psammoma bodies can be seen.
What do we see in the histological findings of follicular carcinoma of the thyroid?
Uniform cuboidal cells lining the follicles. The follicle cells are the cancer but the cuboidal lining keeps them from getting away. It can invade thru the lining, which differentiates it from a follicular adenoma.
What is the preferred way of metastasis of follicular carcinoma?
Hematogenously.
What is medullary carcinoma of the thyroid and what substance does it like to secrete?
Proliferation of parafolicullar C cells. They secrete calcitonin.
What 2 structures are most vulnerable in thyroid surgery?
- Parathyroid glands: affects calcium levels
2. Recurrent laryngeal nerve: Hoarse voice
What type of thyroid cancer has activation of receptor tyrosine kinases?
Papillary and medullary carcinoma.
Which type of thyroid carcinoma is commonly associated with either a RAS mutation or a PAX8-PPAR gamma 1 rearrangement?
Follicular carcinoma.
Which type of thyroid carcinoma is associated with rearrangements in RET oncogene or NTRK1?
Papillary carcinoma.
Which type of thyroid carcinoma is associated with most common mutation in the BRAF gene?
Papillary carcinoma.
What are some of the symptoms of hypothyroidism?
Cold intolerance, weight gain, constipation, lowering of the voice, menorrhagia, slowed mental and physical function, dry skin with coarse, brittle hair, reflexes showing slow return phase.
