Flashcards in Neoplasm of the Thyroid Gland Deck (18)
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1
How does thyroid NEOPLASIA classically present?
- distinct, SOLITARY nodule.
2
Are thyroid nodules more likely to be malignant or benign?
- BENIGN
3
What study can you do if you think a pt has a thyroid neoplasia?
- radioactive iodine uptake study
*will see INCREASED uptake in Graves or nodular goiter.
*will see DECREASED uptake in adenoma and carcinoma (warrants FNA biopsy).
4
*** If you have DECREASED radioactive iodine uptake, what type of biopsy should you do?
- FINE NEEDLE ASPIRATION (FNA) biopsy.
5
What is a Follicular adenoma?
- BENIGN proliferation of follicles surrounded by a FIBROUS CAPSULE.
- usually nonfunctional; rarely may secrete thyroid hormone.
*HURTHLE cell subtype= eosinophilic cytoplasm.
6
**** What is a Papillary carcinoma?
- MOST COMMON type of thyroid carcinoma.
- forms papillary fingerlike projections.
- ORPHAN ANNIE NUCLEI= white clearing in center of nuclei.
- NUCLEAR GROOVES.
- PSAMMOMA BODY= layering of calcium.
- exposure to IONIZING RADIATION in childhood is a major risk factor.
7
Where does Papillary carcinoma often spread?
- to cervical nodes, but has EXCELLENT prognosis :)
8
**** What is a Follicular carcinoma?
- MALIGNANT proliferation of FOLLICLES.
- surrounded by a FIBROUS CAPSULE with INVASION through the capsule.
- PI-3K/AKT, RAS, PTEN, PAX8, or PPARG mutations
9
Can fine needle biopsy distinguish between follicular adenoma and follicular carcinoma?
- NO, bc you need to examine the capsule.
10
How does Follicular carcinoma metastasize?
- HEMATOGENOUSLY
*odd bc normally carcinoma spreads via lymphatics.
11
What is Medullary carcinoma?
- MALIGNANT proliferation of parafollicular C-cells (sit adjacent to follicles).
- high levels of CALCITONIN produced by tumor and may lead to HYPOcalcemia.
*calcitonin often deposits within tumor as AMYLOID; aka localized amyloidosis.
12
**** What are some familial cases of Medullary carcinoma of the thyroid?
- due to Multiple Endocrine Neoplasia (MEN2A) and (2B).
- associated with mutations in RET ONCOGENE.
*detection of RET mutation warrants prophylactic thyroidectomy.
13
What 3 neoplasias are associated with MEN2A?
1. medullary carcinoma of THYROID
2. PHEOCHROMOCYTOMA (adrenals)
3. PARATHYROID adenoma
14
What 3 neoplasias are associated with MEN2B
1. medullary carcinoma of THYROID
2. PHEOCHROMOCYTOMA (adrenals)
3. GANGLIONEUROMAS (particularly of oral mucosa).
15
*** What is Anaplastic carcinoma of the thyroid?
- undifferentiated MALIGNANT tumor of thyroid.
- usually seen in ELDERLY.
- often invades local structures leading to DYSHPAGIA or RESPIRATORY compromise.
- may be positive for cytokeratin.
- RAS or PIK3 mutations.
*poor prognosis.
16
Remember, what does anaplastic carcinoma mimic?
- Reidel Fibrosing Thyroiditis, but this would be in a YOUNG FEMALE.
17
Do thyroid adenomas generally give rise to carcinoma?
- NO (unlike the GI tract).
18
