Endocrine University 2014 Flashcards
How big does a thyroid nodule need to be to be detected by thyroid ultrasonography?
2 - 3 mm
How much does the thyroid gland weigh?
20 - 25 grams
Describe echogenicity of normal thyroid gland on thyroid ultrasonography.
High intensity homogeneous echo pattern with little identifiable internal architecture.
Describe echogenicity of Hashimoto’s thyroiditis on thyroid ultrasonography.
Heterogeneous hypoechoic echotexture.
How thick is a normal thyroid isthmus?
Less than 5 mm
How do you measure the volume of the thyroid gland on ultrasonography?
Calculate volume by multiplying the three dimensions (W x D x L) and then multiplying by a correction factor (formula of an ellipsoid).
Traditional correction factor: pi/6 = 0.524
WHO recommendation: 0.479
Acceptable correction factors: 0.494 - 0.554.
What is a nodule with a hilar line on thyroid ultrasonography?
Lymph node
What happens to the lymph nodes in Hashimoto’s thyroiditis?
Matted clustered nodes, often with abnormal shape and loss of hilar line.
Frequency of which cancer is increased in Hashimoto’s thyroiditis?
Papillary thyroid cancer.
What should you do when you feel a thyroid nodule?
Get a thyroid ultrasound.
Thyroid Ultrasonography
Are benign nodules more likely to be hyper- or hypoechoic?
Hyperechoic
Thyroid Ultrasonography
Smooth margin often with a ‘halo’.
More likely to be:
Benign or malignant?
Benign
Thyroid Ultrasonography
Thick, irregular halo.
More likely to be:
Benign or malignant?
More suggestive of malignancy.
Follicular or Hurthle cell carcinoma or adenoma.
Encapsulated papillary cancer follicular variant.
Thyroid Ultrasonography
Thin-walled cyst without a solid component.
More likely to be:
Benign or malignant?
Benign.
Thyroid Ultrasonography
Colloid within cystic nodule - comet tail or ‘cat’s eye’.
More likely to be:
Benign or malignant?
Benign
Thyroid Ultrasonography
Intact eggshell calcification.
More likely to be:
Benign or malignant?
Benign
Thyroid Ultrasonography
Interrupted eggshell calcifications.
More likely to be:
Benign or malignant?
More likely malignant.
Thyroid Ultrasonography
Low vascularity.
More likely to be:
Benign or malignant?
Benign.
Thyroid Ultrasonography
Multiple blocks of hyperechogenicity separated by bands of hypoechogenicity.
More likely to be:
Benign or malignant?
Benign
Thyroid Ultrasonography
Do discrete nodules need to be evaluated individually?
Yes
Thyroid Ultrasonography
Spongiform echotexture.
More likely to be:
Benign or malignant?
Benign
Only 1 in 360 cancers have this appearance.
Specificity: 99.7%
Thyroid Ultrasonography
Name the nodules with the following descriptions:
- aggregation of multiple microcystic components in more than 50% of the volume of the nodule.
- “honeycomb of internal cystic spaces”
“Spongiform” nodules
What is the best indication of a benign thyroid nodule on thyroid ultrasonography?
Shrinkage of a nodule over time.
Thyroid Ultrasonography
Hypoechoic solid nodule.
More likely to be:
Benign or malignant?
Malignant
Thyroid Ultrasonography
What are the following characteristics suggestive of?
- Hypoechoic or heterogeneous nodule.
- Irregular or ‘infilterative’ margins.
- Irregular mural component of cyst.
- Invasion of adjacent tissue/muscle.
- Sonographically suspicious cervical lymphadenopathy.
- Microcalcifications/macrocalcifications
- ‘Taller than wide’ shape on transverse view.
Papillary thyroid cancer
Thyroid Ultrasonography
‘Intra-cystic cauliflower appearance’
What is the likely diagnosis?
Cystic papillary carcinoma
Thyroid Ultrasonography
How big are macrocalcifications and what do they look like?
More than 2 mm.
Dense hyperechoic spots with acoustic shadowing.
What is the term ‘thyroid inferno’ used to describe?
Increased vascularity seen on Doppler US in Grave’s Disease.
Is there one definition of ‘adequate sample’ when preparing thyroid slides?
No
Adequate thyroid FNA biopsy according to The Papanicolaou Society of Pathology …
6 - 8 groups of well preserved follicular cells with 10 or more cells per group.
“6 groups of 10”
How many surgical levels in the neck are they?
6
Labeled in Roman numerals.
Surgical compartments of the neck:
Compartment I
Submandibular to the hyoid bone in the center (under the chin).
Surgical compartments of the neck:
Compartment VI
From the submandibular notch to the hyoid bone - in the center of the neck.
Surgical compartments of the neck:
Compartment V
Posterior to the sternocleidomastoid.
Surgical compartments of the neck:
Compartment IV
From the clavicle to the cricoid cartilage deep to the sternocleidomastoid on the lateral sides of the neck.
Surgical compartments of the neck:
Compartment III
Between the cricoid cartilage and the hyoid bone deep to the sternocleidomastoid on the lateral sides of the neck.
Surgical compartments of the neck:
Compartment II
From the hyoid bone to the base of the skull and angle of the mandible.
IIB - deep to the sternocleidomastoid.
IIA - anterior to the sternocleidomastoid.
Does prophylactic lateral neck dissection improve recurrence free survival in patients with preoperative US negative for lymph nodes?
No
Does lateral neck dissection alter the outcome in patients with preoperative US positive for lymph nodes?
Modified neck dissection at the time of initial thyroidectomy improves survival if there is ‘macroscopic’ lateral lymph node metastasis on ultrasonography.
What should be done when an abnormal/suspicious lymph node is detected on thyroid ultrasonography?
If a positive result would change management then the lymph node should be biopsied for cytology with thyroglobulin measurement in the needle wash out fluid.
How big does an abnormal lymph node found on thyroid US have to be before it can be biopsied?
Greater than 5 - 8 mm in its smallest diameter.
What gauge needle should you use for thyroid FNA biopsy?
25 - 27 gauge
What gauge needle should you use for draining thyroid cysts?
22 gauge
If there is blood in the hub is the dwell time too long or too short?
Too long.
Which receptor is cabergoline specific for?
D2
Which drug has been shown to be more likely to cause valvular abnormalities - bromocriptine or cabergoline?
Cabergoline
When was I-131 discovered?
1938
Who discovered I-131?
Glen Seaborg
What is the half life of I-131?
8 days
Do Doppler grades apply to parathyroid glands?
No
Is the brand name of the machine and the mHz of the probe relevant to the thyroid ultrasound report?
No
Which two words do you use to describe the texture of the thyroid gland on ultrasonography?
Heterogeneous
Homogeneous
Does growth hormone deficiency persist into adulthood?
It does usually persist.
What is the AACE recommended HbA1c goal for patients without concurrent illness and at low risk for hypoglycemia?
6.5% or less.
Name two alpha glucosidase inhibitors.
Acarbose.
Miglitol.
What is the mechanism of action of alpha-glucosidase inhibitors?
Delays/decreases carbohydrate absorption from the intestine.
Name one amylin analogue.
Pramlintide.
What is the mechanism of action of amylin analogues?
3 points
- Decreases glucagon secretion.
- Slows gastric emptying.
- Increases satiety.
What is the mechanism of action of biguanides?
2 points
- Decreases HGP
- Increases glucose uptake in muscle.
Name one bile acid sequestrant.
Colesevelam
Name four DPP-4 inhibitors.
Saxagliptin
Sitagliptin
Linagliptin
Alogliptin
What is the mechanism of action of DPP-4 inhibitors?
2 points
- Increase glucose-dependent insulin secretion.
- Decreases glucagon secretion.
Brand Name: Nesina
Generic: ?
Alogliptin
Brand name: Tradjenta
Generic: ?
Linaglipin
Brand Name: Onglyza
Generic: ?
Saxagliptin
Brand Name: Januvia
Generic: ?
Sitagliptin
Brand Name: Cycloset
Generic: ?
Bromocriptine
Name two glinides.
Nateglinide
Repaglinide
Brand Name: Starlix
Generic: ?
Nateglinide.
Brand Name: Prandin
Generic: ?
Repaglinide.
What is the mechanism of action of glinides?
Increase insulin secretion.
What is the mechanism of action of GLP-1 inhibitors?
Four points
- Increases glucose-dependent insulin secretion.
- Decreases glucagon secretion.
- Slows gastric emptying.
- Increases satiety.
Brand Name: Byetta
Generic: ?
Exenatide
Brand Name: Bydureon XR
Generic: ?
Exenatide XR
Brand Name: Victoza
Generic: ?
Liraglutide
What is the mechanism of action of SGLT2 inhibitors?
Increases urinary excretion of glucose.
Brand Name: Invokana
Generic: ?
Canagliflozin
Brand Name: Amaryl
Generic: ?
Glimipiride.
Brand Name: Glucotrol
Generic: ?
Glipizide.
Brand Name: Actos
Generic: ?
Pioglitazone
Brand Name: Avandia
Generic: ?
Rosiglitazone.
Brand Name: Glynase
Generic: ?
Glyburide.
Brand Name: Diabeta
Generic: ?
Glyburide.
Brand Name: Micronase
Generic: ?
Glyburide
What is the mechanism of action of thiazolidinediones?
Two points
- Increases glucose uptake in the muscle and fat.
- Decreases HGP
For diagnosing a pheochromocytoma, which is more reliable…
Imaging phenotype or biochemical testing?
Imaging phenotype.
What should the Hounsfield units be if an adrenal mass is suspicious for a pheochromocytoma?
Greater than 20 Hounsfield Units.
What should the contrast washout be if an adrenal mass is suspicious for a pheochromocytoma?
Less than 50% contrast washout at 10 minutes.
Where are epinephrine/metanephrine predominant tumors usually localised to?
(Hint: two places)
- Adrenal medulla
- Organ of Zuckerkandl
Where are norepinephrine/normetanephrine predominant tumors usually localised to?
(Hint: two places)
- Adrenal medulla
- Sympathetic paraganglioma in the neck, chest, abdomen or pelvis.
What is the TSH target for women before conception?
0.3 - 2.5 mIU/L
What is the TSH target in the first trimester of pregnancy?
0.01 - 2.5 mIU/L
What is the TSH target for the second and third trimester of pregnancy?
0.01 - 3 mIU/L