Thyroid FNA Part 1 Flashcards
Bi-lobed endocrine gland
Located in the anterior neck between the C5 and T1 vertebrae
Connected by an Isthmus
Wraps around the cricoid cartilage
Thyroid Gland
Two paired arteries provide the blood supply for the thyroid, what are they?
Superior and the inferior thyroid arteries
Thyrotropin-Releasing Hormone binds to receptors on endocrine cells w/in Anterior pituitary => stimulating endocrine cells to => synthesize & secrete —– ?
Thyroid-stimulating hormone (TSH)
There is a Thyroid —– loop that occurs in Thyroid
Feedback loop
TRH then enters bridge b/w hypothalamus & anterior pituitary gland —
What is the name of this bridge which is also known as a capillary bed?
Hypophyseal portal system
2 types of hormones secreted by Thyroid?
T3 & T4
Differentiate b/w the 2 types of Thyroid hormones
T3 is scarcer but 4x more potent than T4 which is more prevalent
Why are the hormones referred to as T3 & T4?
T3: Triiodothyronine; contains 3 iodides
T4: Thyroxine; contains 4 iodide molecules
Although both T3 & T4 winds up in systemic circulation, which gets converted to which?
T4 gets converted into T3
TH targets the —- which causes —–
resulting in plasma glucose level increasing
Liver, Glycogenolysis,
Thyroid is organized into pools of hormones and stabilizing proteins stored outside the cell as —–
Colloid
Colloid is bound in a spherical fashion by —-?
follicular cells
—– is the functional unit of the thyroid
Thyroid Follicle
Follicular cell function- produce store and release thyroid hormones upon stimulation by pituitary-derived —- ?
TSH
——- present in the thyroid which acts as substrate for synthesis of Thyroxine (T3) and triiodothyronine (T4)
Thyroglobulin- base glycoprotein
Divided into lobules of 20-40 round to oval follicles, each 50-500 microns, with a single layer of —— to low —— ?
cuboidal, columnar epithelium
Stroma contains —— , formerly called parafollicular cells (actually are intrafollicular), derived from —–
C cells, neural crest
Which cells produces Calcitonin?
C cells
Parathyroid —— calcium in blood while Calcitonin —— the calcium in blood
increases, decreases
—- are present behind the thyroid &
produce parathyroid hormone; done by the —–
Parathyroid glands, chief cells
Composed of chief cells (hormone secreting) and granular mitochondria rich oxyphilic cells
Parathyroid Glands
Colloid follicle is lined by what type of epithelium?
non-stratified, cuboidal epithelium
Increased iodine uptake produces —— ?
“Hot” nodules: darker in color
Decreased iodine uptake produces —– ?
“Cold” Nodules: Lighter in color
Hormone producing
Flat to cuboidal to columnar in shape
Honeycomb sheets
Cell borders are not prominent
Active follicular cells have more cytoplasm
Nuclei do not crowd or overlap each other
Very small, around the cell of RBC
Follicular Cells
Round to oval nuclei
Appr. The size of a lymphocyte
Smooth membranes
Granular chromatin
Hyperchromatic
Small nucleoli may be present
Benign Follicular Cells
Large
Granular eosinophilic cytoplasm
Hyperchromatic nuclei
Small nucleoli
Polygonal
Hurtle Cells
These cells were first described/named when found in which animal?
A dog
Non-functional oncocytic cells
Follicular cells which become packed with mitochondria
Thyroglobulin (+)
Hurtle Cells
Abundant granular cytoplasm
Purple on (MGG) blue to orange on (Pap)
Nuclei are often eccentrically located
Enlarged nuclei
Binucleation common
Fine to coarse Chromatin
Hurtle Cells
—- cells have HUGE nucleoli at times, coarse chromatin
Hurtle Cells
Contains pools of thyroid hormones
Pink to Gray on Pap
Watery substance
Blue to violet on Diff-Quik
Colloid
Orange core & blue outer edges on Paps
Colloid
What is the follow-up for Thyroid?
6 mos
Adequacy for Thyroid
6 groups of well visualized follicular cells w/ 10 cells per group
—- denotes ANY enlargement of Thyroid glands
Goiter
What is the most commonly encountered Thyroid entity
Goiter
Super cellular
Small round dark cells that are columnar-cuboidal
Macrofollicular fashion
Adenomatous Goiter (Nodular)
Abundant thick watery colloid in the absence of follicular cells can be deemed a benign —- ?
colloid goiter
Subacute Thyroiditis also known as —- or —– ?
DeQuervain’s Thyroiditis or Granulomatous Thyroiditis
Cytology:
- Follicular cells, epitheloid histocytes and multinucleated giant cells (Langhans type)
Lymphocytes, plasma cells ,eosinophils
Thyroiditis
Another name for CHR Thyroiditis is —-?
Lymphocytic/Hashimoto’s Thyroiditis
What cells should you see in Hashimoto’s Thyroiditis?
Hurtle cells (oncocytes) + Lyc
Graves Disease is termed as —– ?
Hyperthyroidism
Consists of goiter, tremor, flushed skin, exophthalmos (eyeball protrusion)
Hyperthyroidism
Cytology:
-Tall columnar follicular cells
-Paucicellular
-Increased cytoplasm
-Colloid within the vacuoles of follicular cells with bright red staining called “flame cells”
Hyperthyroidism
Cause of hyperparathyroidism
Hypercalcemia, loss of phosphate
Possible renal failure
May occur in patients with MEN
Typically small
Parathyroid Adenoma
Absence of colloid
Composed mainly of chief cells with clear cytoplasm
Similar appearance to thyroid (diagnostic problem)
Honeycomb pattern
No single morphologic criteria can separate PTA from MNG
Parathyroid Adenoma
Why can a parathyroid Adenoma cause kidney failure?
It causes hypercalcemia which causes too much Ca2+ in blood - can cause kidney to fail
