Thyroid Pathology Flashcards
Lesion architecture/growth patterns of thyroid lesions
follicular, papillary, solid, trabecular w/ fibrosis, calcifications, or amyloid
T/F thyroid lesions with calcifications should be biopsied
T
Papillary formation
hyperplastic proliferation of follicular epithelium results in invagination of cells into lumen of follicle –> VEGF mediated central blood supply –> papillary formation
T/F multiple/solitary nodules are usually benign
multiple –> usually benign but can have neoplasm in background
2 main types of diffuse thyroid enlargements
hyper: diffuse toxic goiter (Graves)
hypo: chronic lymphocytic thyroiditis (Hashimoto’s)
Graves Disease: increase/decrease in colloid
decrease
Graves Disease: increase/decrease in vascularity
increase
Histological features of Graves
follicular hyperplasia, lymphocytic infiltration in stroma
T/F there is hyperplasia in hashimotos
F
Histologic features of hashimoto’s
infiltration of lymphocytes and plasma cells, follicular atrophy, oncocytic metaplasia
T/F atrophic colloid is functional
F
Hurthle cell
oncocytic –> metaplastic follicular cell
T/F lymphocytic metaplasia in hashimoto’s is limited to stroma
F –> throughout gland vs. only in stroma in Graves
At least ___% of US pop has thyroid nodules.
60%
C cells are located in the lateral/medial thyroid
lateral
Malignant tumor of c cells
medullary carcinoma
C cell hyperplasia is found in _____ syndrome
MEN 2
Gross pathology of non toxic goiter
firm, diffusely enlarged –> rough multinodular, calcification, fibrosis, cystic degeneration
T/F calcifications can be found in benign and malignant nodules
T
T/F non toxic nodular goiters are non-heterogeneous on histologic exam
T
Histologic features of non toxic nodular goiters
large and small follicles, columnar or cuboidal epithelium, follicular hyperplasia/papillary growth, fibrosis
fibrosis in non toxic nodular goiter
thyroid nodules outgrow blood supply –> degeneration of nodules –> fibrosis
Most common thyroid neoplasm
well-differentiated thyroid neoplasm –> same architecture (follicles and papillae) –> still produce Tg
Most common benign thyroid epithelial neoplasm
follicular adenoma –> white circumscribed capsule
Malignant tumors of thyroid are more common in M/F
F –> nodules in general more common in women
Most thyroid carcinomas are indolent/aggressive
indolent –> can treat with radioactive iodine b/c well differentiated still can absorb iodine and have functional receptors
Most well known etiological factor for thyroid carcinoma
irradiation especially in childhood (Chernobyl) leading to papillary carcinoma
Which gene rearrangements are common to irradiation of thyroid
Ret oncogene (in addition to RAS, BRAF, p53, APC)
Which carcinoma is the primary result of thyroid irradiation
Papillary carcinoma (well differentiated malignant neoplasm of thyroid)
T/F thyroid carcinoma due to irradiation can result from mutations
F –> rearrangements
RET
rearranged in endocrine tumors –> chimeric oncogene on chr10 –> overactivation of tk domain
T/F RET/PTC is specific to papillary thyroid carcinoma
T
Two main well differentiated follicular cell carcinomas
PTC, follicular carcinomas
PTC is common to iodine sufficient/deficient regions
sufficient
PTC are known as micro/macro carcinomas
micro
T/F 30% of US pop has a microcarcinoma in thyroid
T
Where does PTC metastasize to?
lymph nodes
Dx of PTC
nuclear features NOT invasive growth
Histologic features of PTC
nuclear inclusion/groove, elongated cells, clear nuclei
Tall cells
tall cell variant of PTC has really tall cells
Variants of PTC
papillary, follicular, tall cell
10 year survival of PTC
90%
Risk factors for PTC aggressive growth
male, older age, tall cell, distant mets
Follicular carcinoma is common in iodine deficient/sufficient areas
deficient
T/F follicular carcinoma shows up with older age
T
T/F PTC can present at all ages
T
T/F Follicular carcinoma are encapsulated
T –> like an adenoma except with invasion of tumor capsule and capsule vessels
How does Follicular carcinoma metastasize
hematogenous spread
Papillary or Follicular? most common thyroid cancer
papillary
Papillary or Follicular? Dx based on nuclear morphology
papillary
Papillary or Follicular? dx based on invasion
follicular
Papillary or Follicular? mets via lymph
PTC
Papillary or Follicular? mets via blood
follicular
Papillary or Follicular? multiple tumors
PTC
Papillary or Follicular? single tumor
follicular
Papillary or Follicular? ras mutations
follicular
Papillary or Follicular? ret mutations
PTC
c cell derived carcinoma
medullary carcinoma
Medullary carcinoma involves mutations of _____ oncogene
Ret
Tumor nest
pathologic feature of medullary carcinoma with amyloid background
Medullary carcinoma produces ____
calcitonin
T/F can treat medullary carcinoma with radioactive iodine
F
5 year prognosis of medullary carcinoma
50%
Amyloid in thyroid indicates ____
medullary carcinoma –> byproduct of calcitonin production
Medullary carcinoma metastasizes via
blood and lymph
Dx medullary carcinoma
cytology or calcitonin stain or measure calcitonin levels
Anaplastic carcinoma of thyroid
fatal, 5% of thyroid malignancies, pt’s over 60
Most aggressive tumor of thyroid/body
anaplastic carcinoma
T/F anaplastic carcinoma often preceded by hx of goiter
T –> multinodular more common
Anaplastic carcinoma more common in M/F
F
T/F Anaplastic carcinomas can be treated with radioactive iodine
F –> not well differentiated and does not produce Tg
Histology of anaplastic carcinoma
Multinucleated giant cells, pleomorphic, spindle cells
