ENDOC- THYROID Flashcards
Describe the anatomy of the thyroid.
- Paired lobes of near-equal size (5 × 2 × 2 cm)
- connected by isthmus
Describe the parenchyma of thyroid.
Parenchyma: Homogeneous with fine medium-level echogenicity greater than that of the muscle.
The thyroid’s anatomic landmarks are:
Midline
Anatomic landmarks:
- : air-filled trachea which casts an air shadow
The thyroid’s anatomic landmarks are:
Lateral edge:______________
common carotid artery and internal jugular vein
The thyroid’s anatomic landmarks are:
Posteriorly:________________
longus colli muscles
The thyroid’s anatomic landmarks are:
Anteriorly:
- sternohyoid,
- sternothyroid,
- and sternocleidomastoid muscles
connected across the trachea by a thin thyroid______________
isthmus
The thyroid lobes are often _______________ in size.
mildly asymmetric
The ______________-** commonly protrudes** from behind the trachea, nearly always on the left side, and must not be mistaken for a thyroid or parathyroid mass or lymph node (Fig.
esophagus

In the UTZ of the Thyroid, what probe is used and why?
We use the LINEAR PROBE
Because Linear probe is used only for superficial organs and Thyroid is an example.
NOTE: The CURVE probe is used for deep seated organs.
What is the ◦First choice and the most sensitive imaging modality for thyroid?
§Ultrasound
Note : can give anatomical but not FUNCTIONAL
◦ provides excellent functional information about the thyroid gland
“Hot” or “Cold
Thyroid scintigraphy
Note: Can give FUNCTIONAL but less of ANATOMICAL incontrast with UTZ
In thyroid scintigraphy:
HOT :
DARKER
In thyroid scintigraphy,
COLD:
lighter
Nmemonics: Hot place: DARKER people
Cold place: Lighter People

Thyroid Hot and Cold Scintigraphy
Extremely common:
◦4% to 8% of adults have palpable nodules
◦10% to 41% have nodules on US examination
◦50% have nodules at autopsy.
Increase in frequency with age
** More common in women. **
Thyroid Nodules
How many percent of the adult have thyroid nodules?
4% to 8%
What gender is more common for Thyroid nodules?
Female
” Tandaan kasi baka dahil sa when going through pregnancy dba increase thyroid hormones.. baka lng.. link link hehe”
What are the parameters of Malignant Thyroid nodules?
- Iso- or HYPERechoic
- MACROcalcifications
- Regular border
- No infiltrative margins
- absent of abnormal cervical lymph nodes
- Periphery nodular vascularity
What are the parameters of malignant Thyroid nodules in UTZ?
- Hypoechoic
- Microcalcifications
- Border irregularity
- infiltrative margins
- abnormal cervical lymph nodes
- Increased intranodular vascularity
What are your BENIGN THYROID NODULES?
ØAdenomatous nodules
ØFollicular adenoma
ØThyroid cyst
ØHemorrhage
NMEMONICS: FATH
Thyroid cancer, on the other hand, affects only ____________ of the population.
Thyroid cancer is less than 1% of all cancer and is the cause of less than 0.5% of all cancer deaths.
Most thyroid cancers are slow growing and have low morbidity and mortality.
0.1%
The ratio of benign thyroid nodules to thyroid cancer can be estimated at as high as ____________-.
The challenge of imaging studies and clinical evaluation is to establish the likelihood of malignancy and to select out for surgery only those patients with thyroid malignancy.
500:1
select out for surgery only those patients with_________________
** thyroid malignancy.**
- Colloid nodules**
- Most common thyroid nodule.**
Adenomatous Nodules
Adenomatous Nodules result from the_____________
Growths resulting from cycles of hyperplasia and involution of thyroid tissue
Multiple and associated with diffuse enlargement of the thyroid gland.
What are the imaging finding of Adenomatous Nodules?
Imaging findings:
◦Isoechoic or hypoechoic to thyroid parenchyma
◦May show degenerative changes with prominent cystic components, necrosis, hemorrhage, and calcification

dominant nodule (between arrowheads) with cystic change (arrow) measuring 18 mm in greatest dimension.
This nodule meets the Society of Radiologists in Ultrasound criteria for fine-needle aspiration (FNA).
US-guided FNA biopsy yielded a cytologic diagnosis of “colloid nodule” indicating visualization of benign thyroid cells and thyroid colloid.
Note the homogeneous pattern of the visualized normal thyroid parenchyma (Thy).
Most common benign neoplasm
Autonomous hyperfunctioning adenomas
◦Hyperthyroidism
Follicular Adenoma
What are the imaging finding of Follicular Adenoma?
Imaging findings:
◦Most are solitary, solid, and well encapsulated.
◦Hypoechoic, hyperechoic, or isoechoic to thyroid parenchyma
◦Hyperfunctioning adenomas = strikingly hypervascular on Doppler US.
◦Degenerative changes
Hyperfunctioning adenoma appears ___________ on Doppler UTZ
◦Hyperfunctioning adenomas = strikingly hypervascular on Doppler US.
cause no alteration of overall thyroid function.
include focal necrosis, hemorrhage, edema, infarction, fibrosis, and calcification.
Differentiation from follicular carcinoma is difficult; therefore an ___________________________ is commonly considered an indication for surgical removal and histologic determination of the presence of cancer.
FNA cytologic diagnosis of follicular neoplasm

Follicular Adenoma
Dominant thyroid nodule (between cursors, x, +) with an irregular area of cystic change is evident (arrow).
Because a diagnosis of follicular carcinoma could not be excluded, this lesion was surgically removed.
No histologic evidence
Differentiation from follicular carcinoma is difficult; therefore an FNA cytologic diagnosis of follicular neoplasm is commonly considered an indication for surgical removal and histologic determination of the presence of cancer.

Follicular Adenoma
Showing hypervascularity
- Extremely rare,
- epithelial-lined,
- simple cysts.
- Cystic degeneration of an adenomatous nodule (“colloid cyst”) or a follicular adenoma.
Thyroid Cyst
Colloid Cyst
_______________Comet Tail Artifact.
A sharply defined cystic lesion within the right thyroid lobe shows floating punctate echogenic foci with a tapering tail (arrow).
This comet tail artifact is characteristic of inspissated colloid and a benign lesion.

Colloid Cyst—Comet Tail Artifact. A sharply defined cystic lesion within the right thyroid lobe shows floating punctate echogenic foci with a tapering tail (arrow).
This comet tail artifact is characteristic of inspissated colloid and a benign lesion.
This comet tail artifact is characteristic of _______________
inspissated colloid and a benign lesion.
May occur into an adenomatous nodule or a follicular adenoma, or spontaneously into normal parenchyma.
Patients present with sudden neck pain and subsequent swelling.
Hemorrhage
Imaging Findings Of Hemorrhage in
Ultrasound:
** hypo**echoic nodule with internal debris.

Ultrasound: hypoechoic nodule with internal debris.
Malignant Thyroid Nodules
§Papillary thyroid carcinoma
§Follicular thyroid carcinoma
§Medullary thyroid carcinoma
§Anaplastic thyroid carcinoma
§Others:
§Lymphoma
§Metastasis
Among the malignant thyroid nodules this is the most common and comprises 75- 80 %
§Papillary thyroid carcinoma
Follicular thyroid ca is %
10-20%
3-5 % of the malignant thyroid nodules is
Medullary thyroid ca
1-2% of malignant Thyroid nodules is
§Anaplastic thyroid carcinoma
least aggressive cancers in human.
Female (4:1)
Papillary Thyroid Carcinoma
What is the imaging finding in Papillary Thyroid Ca
Imaging Findings:
- ◦Nodules are hypoechoic and commonly multiple.
- ◦Punctate internal calcifications (Psammoma bodies,42%)
- ◦Characteristic parenhymal microcalcifications without a discrete mass present.
- **◦Cervical nodes may contain similar calcifications. **
in papillary thyroid CA___________,42%) and highly indicative of malignancy
Psammoma bodies
The Papillary thyroid CA tumor spreads commonly to regional nodes, but rarely ____________ spreads to lung or bone. Five-year survival is 95% to 99%.
(2% to 3%)

Papillary Thyroid Carcinoma
Papillary Carcinoma of the Thyroid—Microcalcifications. Longitudinal image reveals a solid nodule containing numerous punctate nonshadowing echogenic foci characteristic of microcalcifications associated with papillary carcinoma indicative of malignancy. Biopsy proved papillary carcinoma.
** characteristic of microcalcifications** associated with papillary carcinoma indicative of malignancy. Biopsy proved papillary carcinoma.
** solid nodule** containing numerous punctate nonshadowing echogenic foci
** Slow-growing malignancy**
** Blood vessels invasion = Characteristic!**
Hematogenous spread to lung and bone.
** Male gender** and older age
Follicular Thyroid Carcinoma
What is the imaging finding of Follicular Thyroid CA?
◦Solitary, isoechoic, and ill defined.
◦Cystic areas, hemorrhage, and necrosis
Larger size, lack of an echolucent halo, hypoechoic appearance, and absence of cystic change
In Follicular Thyroid CA Clinical features that favor malignancy are ____________. Five-year survival is about 65%.cal nodes is uncommon.
male gender and older age
The sonographic features of follicular carcinoma
Features that favor carcinoma over adenoma include
larger size, lack of an echolucent halo, hypoechoic appearance, and absence of cystic change
Microlcalcification of > or =1 cm
Strongly consider US- guided FNA
Solid) almost entirely or with central calcification)
> or = 1.5 cm
Stongly consider US-guided FNA
Mixed solid and cystic or almost entirely cystic with a solid mural component
> or = 2 cm
Consider US- guided FNA
Substantial growth since prior US
ConsiderUS-guided FNA
Almost entirely cystic with none of the above and no substantial growth ( or no prior US)
US-guided FNA probably not necessary
Multiple nodules
Consider US-guided FNA of one or more of the nodule selected by criteria listed for solitary nodules