Approach to the Thyroid Nodule Flashcards
label the basic thyroid anatomy
besides a thyroid nodule, what else could the neck mass be?
- congenital; thyroglossal duct cysts, branchial cleft cysts, dermoid cysts
- inflammatory: infection, abscess, lymphadenitis
- neoplastic: metastatic lymph nodes, salivary gland tumors, carotid body tumors
enalrged thyroid?
no. branchial cleft cysts
enlaarged thyroid?
no. submandicular gland tumour; pleomorphic adenoma. it’s too high and lateral.
enlarged thyroid?
yes. huge goiter
Prevalence of Thyroid Nodules
Palpable in 5-10% of all adults
Incidental discovery on ultrasound up to 50%!
Autopsy ~ 50% +
~ 5-10% of all nodules are malignant
which gender is more predisposed to thyroid nodules? age?
females>males :3-4x more prevalent
- age; nodules found in >70% of people over the age of 70.
- countries/regiosn with lower iodine intake or rate of iodine supplementation of salt
benign causes of thyroid nodules
- multinodular goiter
- hashimoto’s thyroiditis (causes hyerthyroid in early stages)
- cysts; collod, simple, hemorrhagic
- follocular adenomas; macro or micro follicular
- hurthle cell adenomas
general aspects of physcial exam when looking at a neck nodules
- location
- does it move while swallowing?
- size
- texture
- borders
- tenderness
- fixed or free?
- pulsaltality
- other symptoms
malignant causes of thyroid nodules
- papillary
- follicular
- hurthle cell
- poorly diferentiatied
- medullary
- thyroid lymphoma
- anaplastic
- metastatic
note different pathogenesis/causes of thyroid cancers
clinical features HIGHLy SUSPICIOUS for malignancy
- rapid growth, especially if on L-__
- very __ or __ nodule
- __ to adjacent strucures
- new persistent __ due to vocal cord paralysis
- regional __ in the lymph nodes
- distant __
- FAMILY HISOTYR of __ __ Cancer or ___ gene
- rapid growth, especially if on L-THYROXINE
- very FIRM or HARD nodule
- FIXATION to adjacent strucures
- new persistent HOARSENESS due to vocal cord paralysis
- regional LYMPHADENOPATHY in the lymph nodes
- distant METASTASES
- FAMILY HISOTYR of MEDULLAR THYROID Cancer or MEN2
Clinical features that increase suspicion for malignancy
- history of head and neck __ treatment
- large _ nodule >4cm
- symptoms of COMPRESSION: __ or __
- incidental discovery on a __ scan.
- history of head and neck RADIATION treatment
- large SOLIDARY nodule >4cm
- symptoms of COMPRESSION: STRIDOR or DYSPHAGIA
- incidental discovery on a PET scan.
Work-up and approach to a thyroid nodule:
imaging; all palpable thyroid nodules and all nodules found incidnetally with other modalities need a dedicated thyroid __.
labs; __ ALONE is all that is required.
imaging; all palpable thyroid nodules and all nodules found incidnetally with other modalities need a dedicated thyroid ULTRASOUND.
labs; TSH ALONE is all that is required.
4 key features on ultrasound of a thyroid nodule that may suggest higher cancer risk
- microcalcification
- irregular borders
- taller than wide
- hypoechoic.
- a combination of these features increases cancer suspicion.
- cannot differentiate between benign and malignant, but may help you to risk stratify nodules for risk of malignancy. You can prioritize the need for biopsy/more frequent evaluation
evaluate
Spongiform nodule- almost always benign
___ alone is the only lab value you need to start out with
TSH alone is all that is required.
- ONLY if your TSH is LOW will you work-up change. It raises suspicion of TOXIC or HOT nodules. Then you need a Thyroid SCAN.
- Normal or high TSH will not change your subsequent investifation plan.
- ONLY if your TSH is ___ will you work-up change. It raises suspicion of __ or ___ nodules. Then you need a Thyroid SCAN.
- ONLY if your TSH is LOW will you work-up change. It raises suspicion of TOXIC or HOT nodules. Then you need a Thyroid SCAN.
- Normal or high TSH will not change your subsequent investifation plan.
HOT nodules have a LOW TSH.
___ nodules have a LOW TSH
- ___ ___ or toxic hot thyroid follicular adenomas.
- HOT nodules almost always are ___.
- ___ in the TSH receptor alters receptor ___ to the “active” position, which causes LIGAND ___ signal transduction.
This causes constitudivve activation of __-__ RESULTING IN __ thyroid hormone production and thus a ___ TSH.
HOT nodules have a LOW TSH
- AUTONOMOUSLY FUNCTION or toxic hot thyroid follicular adenomas.
- HOT nodules almost always are BENIGN.
- MUTATION in the TSH receptor alters receptor CONFORMATION to the “active” position, which causes LIGAND INDEPENDENT signal transduction.
This causes constitudivve activation of GS-ALPHA RESULTING IN ELEVATED thyroid hormone production and thus a LOW TSH.
hot or cold nodule
hot nodule
hot or cold nodule
cold nodule.
What is the criteria to have a fine need aspirate?
FNA if >1.5cm.
follow if >1.0cm
no FNA or follow up if <1.0cm
Fine Needle Aspiration Biopsy
___ ___is preferred. Better samples; target non-palpable and the solid component of a mixed solid/cystic nodule
- Complications include BLEEDING but it is rare.
- in theory, useful results 80%.
- has reduced unnecessary surgery by 50%
Fine Needle Aspiration Biopsy
ULTRA SOUND GUIDANCE is preferred. Better samples; target non-palpable and the solid component of a mixed solid/cystic nodule
- Complications include BLEEDING but it is rare.
- in theory, useful results 80%.
- has reduced unnecessary surgery by 50%
BENIGN epithelial cells, colloid, and occasional macrophages, typical of a “colloid nodule
Follicular lesion- Indeterminate
MALIGNANT Epithelial cells in a papillary formation from a papillary thyroid carcinoma. Nuclear grooves are also apparent
Outline an integrated algorithm for work=up of a thyroid nodule– when to do imaging, when to do labs etc.
- history and TSH
- TSH is normal or high: DO ULTRASOUND
- if TSH is low, do a THYROID SCAN - FNA
treatment options for BENIGN noduels
- observation
- annual nexk exam
- repeat thyroid ultrasoun in 2 years. If nordule is unchanged, no more routine U/S needed.
- Radioactive iodine for HOT NODULES only
- ETHANOL or THERMAL ABLATION is uncommon unless there’s cosmetic issues.
Treatment options for INDETERMINATE NODULES (Risk 6-40%): you must explain options to the patient.
- close observation. repeat thyroid ultrasound in 6 months
- repeat DNA biopsy
- molecular testing on FNA ample for mutations
- surgical consult for a diagnostic lobectomy.
treatment options for malignant or suspicious nodules
NEED SURGERY
-Stratification for possible post-op adjuvant therapy such
as radioiodine.
40 year old healthy female for a routine exam
You see & palpate a 2 cm right-sided neck lump:
non-tender, well-circumscribed & freely moveable
no palpable nodes or other masses
The rest of your exam is negative
- characterize this ultrasound finding. What’s next to do?
2 cm solid nodule
- hypoechoic
- irregular border
- wider than tall
- microcalcifications noticeable.
- given that it is irregular with microcalcifications, an FNA od the node whould beone. FNA would show epithlial cells in a papillar fomration from a pillary thyroid carcinoma. nuclear grooves are also apparent.
___ THYROID CANCER is the most common.
- usually diagnosis is made iwth a __ __ BIOPSY.
- the classic findings of papillary thyroid cancer is __ CELLS, __ __ INCLUSIONS, and __ BODIES.
- usually more AGGRESSIVE, tall looking cell and diffuse __
PAPILLARY THYROID CANCER is the most common.
- usually diagnosis is made iwth a FINE NEED BIOPSY.
- the classic findings of papillary thyroid cancer is EPITHELIAL CELLS, INTRA NUCLEAR INCLUSIONS, and PSAMMOMA BODIES.
- usually more AGGRESSIVE, tall looking cell and diffuse SCLEROSING
which gender is more likely to be affected by thyroid cancer?
WOMEN are three times more common than men. it is the fastest rising incidence of all cancers in the past decade
T/F we should start screening for thyroid cancer
false. screening that results in the identification of indolent thyroid cancers and treatment of these overdiagnosed cancers may increase the risk of patient harms.
5 classifications of thyroid cancer, what is the most common?
- differentiated thyroid cancer (most common)- papillar, folluclar, hurthle cell
- poorly differentiated
- medullary
- anaplastic
- thyroid lymphoma
pathogenesis of thyroid cancers
SPONTANEOUS or __-induced chromosomal gene __: usually from chimeric genes like RET/PTC. BRAF V600E.
- Unregulated __ KINASE activity which increases tumor development and growth
- activatingmutations in __ genes like RAS which can cause __- __ Dysregulation
- Silencing of tumor ___ genes like DNA HYPERMETHYLATION.
- only 5% of all papillary cancers are familial
SPONTANEOUS or RADIATION-induced chromosomal gene REARRANGEMENT: usually from chimeric genes like RET/PTC. BRAF V600E.
- Unregulated TYROSINE KINASE activity which increases tumor development and growth
- activatingmutations in REGULATOR genes like RAS which can cause CELL- CYCLE Dysregulation
- Silencing of tumor SUPPRESSOR genes like DNA HYPERMETHYLATION.
- only 5% of all papillary cancers are familial
outline the different types of cancers that are more and more de-differentiated
SURGERY
- should be done with __ TO __ MONTHS of diagnosis
- near-total ___ usually recommended for leasions >__CM.
- if under 1 cm, it’s called a __ and not treated aggressively. We should actively surveille.
- recent ATA guidelines suggest the option for a __ for low risk patients.
- should be done with 6 TO 12 MONTHS of diagnosis
- near-total THYROIDECTOMY usually recommended for leasions >1CM.
- if under 1 cm, it’s called a MICROCARINOMA and not treated aggressively. We should actively surveille.
- recent ATA guidelines suggest the option for a lobectomy for low risk patients.
5 steps to the post-operative plan
after surgery:
- evaluate final pathology
- staging to help predict mortality and recurrence
- thyroid hormone replacement and intensity
- discuss possible need for radioactive iodine
- outline follow up plan
most staging systems are designed to predict the risk of moratlity. what are the two staging systems
