Thyroid Cancer Flashcards
Thyroid Anatomy:
The bulk of the gland is located immediately anterior and inferior to the thyroid cartilage.
TRUE or FALSE?
True
Thyroid Anatomy:
50% of individuals have a pyramidal lobe that extends
superiorly from the central aspect of the gland, which is a remnant of the gland’s
embryologic origin.
Name this origin.
thyroglossal duct.
Thyroid Anatomy:
Arterial supply (2)
superior thyroid arteries (branches of the external carotid arteries)
inferior thyroid arteries (branches of the thyrocervical trunk from the subclavian arteries)
Thyroid Anatomy:
Venous drainage (3)
paired superior and middle thyroid veins (drains to the IJV)
inferior thyroid veins (drains to the subclavian and innominate veins)
Thyroid Anatomy:
First-echelon nodes
level 6
(central/visceral compartment)
containing the paralaryngeal, paratracheal, and prelaryngeal (delphian) nodes.
Thyroid Anatomy:
Second-echelon nodes
levels 3 and 4,
level 7
and to a lesser extent, level 2
Thyroid Histology:
What is the structural and functional unit of the gland?
thyroid follicles (formed by numerous lobules)
Thyroid Histology:
What is the histology of the thyroid follicle?
single layer of cuboidal epithelium
Thyroid Histology:
What are the contents of the thyroid follicles?
thyroid follicular cells surrounding a central-lumen colloid, a substance rich in thyroglobulin.
Thyroid Histology:
What cells contain granules of calcitonin?
They are neural crest–derived cells.
parafollicular cells or C cells
Thyroid Histology:
The thyroid is incompletely surrounded by a connective tissue capsule.
TRUE or FALSE?
True.
What is the storage and transport form of thyroid hormone?
thyroxine, or 3,5,3’,5’ iodothyronine
or simply T4
What is the metabolicaly active form of thyroid hormone?
thyronine, or 3,5,3’ iodothyronine
or simply T3
Classifications of thyroid cancer:
What type of thyroid cancer arises from the parafollicular C cells of the thyroid?
MTC
medullary thyroid carcinoma
Classifications of thyroid cancer:
What are the two major subgroups of Differentiated Thyroid Carcinoma (follicular-derived)?
PTC and FC
Classifications of thyroid cancer:
The diagnosis of this differentiated (follicular-derived) carcinoma is entirely predicated on the presence of diagnostic nuclear feature and does not require invasive growth.
PTC
nuclear enlargement, hypochromasia, intranuclear cytoplasmic inclusions (nuclear pseudoinclusions), nuclear grooves, and distinct nucleoli.
Classifications of thyroid cancer:
The diagnosis of FC requires evidence of tumor invasion through the thyroid capsule.
TRUE or FALSE?
False
requires evidence of tumor invasion through the tumor (not the thyroid) capsule.
Classifications of thyroid cancer:
Orphan Annie Eyes
PTC.
After formalin fixation, nuclei may appear pale and
optically clear and resemble “Orphan Annie eyes.”
Classifications of thyroid cancer:
Differentiating between classic PTC, follicular PTC, and oncocytic PTC is important because the management and prognosis are different.
TRUE or FALSE?
False
Classifications of thyroid cancer:
What are the subtypes of PTC that have poor prognoses that sometimes are classified under poorly-differentiated carcinomas?
diffuse sclerosing
tall-cell
columnar
hobnail
Classifications of thyroid cancer, lets step up the confusion.
What is this subtype of differentiated carcinoma, previously classifed as a subtype of follicular carcinoma that is now to be regarded as a separate entity. It was formerly called oncocytic carcinoma (not to be confused with oncocytic variant of PTC)?
cells are large and contain abundant granular eosinophilic cytoplasm and can be found in both benign and other malignant lesions, however to make a diagnosis, they must make up at least 75% of the tumor.
Hurthle cell carcinoma.