H_Review_Thyroid nodules Flashcards
Thyroid nodules
5-14% change of malignancy
Increased risk for malignancy:
- <20 - >70
- Men > Women
- XRT
- FMhx Thryoid cancer
- ? elevated TSH
- Nodules with FDG +ve PET with higher Standardized uptake value (SUV) is often
Familial Factors
Medullary thyroid cancer 25%
- MEN 2A or 2B
- Familial medullary thyroid cancer FMTC
- RET protooncogene mutation
Familial non medullary thyroid cancer
Syndromic
- FAP and Gardner’s
- Colorectal tumors/polyps + extracolonic tumors (osteomas of the skull,thyroid cancer, epidermoid cysts, fibromas)
-
PTEN - hmartoma tumor syndrome
- most commonly lost tumor suppressors in human cancer
- Cowden syndrome / breast, endometrial, thyroid, kidney and colorectalcancers, dermatologic features such as oral and skin papillomas, trichilemmomas,
-
Carneys complex
- most commonly caused by mutations in the PRKAR1A gene
- Myxomas may also occur outside the heart, usually in the skin and breast. Endocrine tumors may manifest as disorders such as Cushing syndrome. The most common endocrine gland manifestation is an ACTH-independent Cushing’s syndrome
- Werner’s
Non Syndromic
- Familial papillary ca
- PTC associated with Renal neoplasis
Palpable nodule - what to do next?
- TSH
- High - Uptake scan / if cold nodule bx
- Low - FNA with US
FNA recommendations
- ATA 2009 -
High risk :
FMHx cancer
XRT at young age
Hx thyroid cancer
FDG +ve PET
MEN2/FMTC associated with RET
Calcitonin > 100
- High risk - with/without US features > 5 MM
- Abnormal Cervical LAD - All sizes
- Microcalcification in nodules > 1 cm
- Solid nodules & hypoechoic > 1 cm
- Solid nodules & hyper/Isoechoic > 1.5 cm
- Mixed cystic/solid w us features > 1.5-2 cm
- Mixed cystic/solid wo us features > 2 cm
- Spongiform nodule > 2cm
- Purely cystic nodules FNA not recommended
High risk Sonographic features
- Microcalcification / Punctate calcifications (denoting dots or tiny holes)
- Hypoechoic
- Increased nodular vascularity
- Infiltrative margins
- Taller than wide
Benign findings
Comet-tail
Seen in cystic nodules with coloid cristals
=
-
.
Cancer / Prevelance / Nodule
- Prevalence of thyroid cancer per patient is independent of number of the nodules
- Prevalence of thyroid cancer per nodule decreases as the number nodules increases
- Each nodule needs to be evaluated
Cytopathology what it means
- Non diagnostic
- Benign
- Atypia of undetermined significance
- Suspicious of follicular neoplasm
- Suspicious for Malignancy (pap)
- Malignant
- Non diagnostic 1-4% cancer
- Repeat FNA
- Benign 0-3% cancer
- Clinical follow up
- Atypia of undetermined significance / 5-15% cancer
- Repeat FNA
- Suspicious of follicular neoplasm / 15-30% cancer
- Surgical lobectomy (Hurthle Cell hyperplasia)
- Suspicious for Malignancy (pap) / 60-75% cancer
- Total/lobar resection
- Malignant / 97-99% cancer
- Total thyroidectomy
Benign Nodule Cytology
Not overlapping
large clump of cells
evenly dispursed
Dark nuclie
Benign nodule cytology II
tissue paper like colloid
amcrophages as well (hemosecrine)
Malignant PCT
look at the nucleus inclusion bodies (clear areas)
Malignant pct
MTC - medullary thyroid cancer
cells are very spidle like , staining for calcitonis
Follicular neoplasm
Follicular neoplasm
Normal cytoplasmic normal
Microfollicular pattern
However they arranged in small groups
Hurthle Cell neoplasm
subtype of follicular neoplasm
- granular cytoplasm / monomorphic
- may have lyphocytic thyroitditis (hashimatos)
Hurthle Cell neoplasm
Molecular markers on Cytology
Papillary thyroid cancer
- BRAF, RET/PTC, RAS
Follicular Carcinomas
- RAS, PAX8/PPARy
Cytology and + ve Mutation = cancer probability 89%
Autonomous nodules
Will have suppressed TSH
Could be solitary vs MNG
/
Follow up for benign nodules
- no real consensus on definition of growth
ATA 2009
Follow up with US in 6-18 months after initial FNA
if Stable in size follow up interval can be increased to 3-5 yrs
If > 50% increase in nodule volume
or > 20% increase in diameter in at least 2 dimensions repeat FNA
