THYROID Flashcards
MEN 1 gene? Located on what Chr?
Menin. AD gene located on Chr 11.
First abnormality typically detected for MEN 1.
hyperCa 2/2 hyperPTH (nephrolithiasis)
Risk thyroid cancer highest in young vs. old, men vs. female?
highest in young AND old, 2x greater risk in men (excision indicated in men >60yo)
Genetic mutation associations: RET
familial medullary thyroid CA
Genetic mutation associations: PAX-8/PPARgamma
follicular thyroid CA
Genetic mutation associations: p53
anaplastic
Genetic mutation associations: BRAF
papillary
Mgmt thyroid lymphoma
chemotherapy (do not need surgery unless compressive sxs)
Mgmt diffuse large B-cell lymphoma
CHOP (cytoxan, hydroxy doxodubicin, oncovin, prednisone) + radiation
Bethesda criteria (6)
for FNA results
- benign = repeat exam in 6-12mo with US
- non-dx (suspicious US, benign FNA; discordinant) = repeat FNA
- follicular cell of indeterminate significance = repeat FNA
- follicular neoplasm = lobectomy
- suspicious for malignancy = lobectomy vs. total thyroidectomy
- malignant = lobectomy vs. total thyroidectomy
MC type thyroid cancer
papillary
Does lymphatic spread affect prognosis of papillary thyroid cancer?
NO. Local invasion does.
Path: papillary thyroid cancer
- psammoma bodies
- orphan annie nuclei
Why total thyroidectomy for papillary thyroid cancer?
- removal of multifocal disease (common 30%), even if cannot see
- preparation for RAI therapy
- so can use thyroglobulin levels to test for recurrence
Germline mutations related to medullary thyroid cancer
- MEN 2A (RET)
- MEN 2B (RET)
- familial medullary thyroid cancer
Serum markers surveillance for medullary thyroid cancer
calcitonin (pentagastrin-stimulated peak plasma calcitonin) + CEA levels q6mo for 1 year, then annually
Anatomical variance associated w/ non-recurrent RIGHT laryngeal nerve
aberrant RIGHT subclavian artery (arteria dosoria)
Serum marker surveillance for papillary thyroid cancer
thyroglobulin
MC sxs of high level calcitonin in blood
diarrhea
MEN2A: what age need prophylactic thyroidectomy?
6yo
MEN2B: what age need prophylactic thyroidectomy
<2yo
Superior thyroid artery runs adjacent to what nerve?
superior laryngeal nerve
Inferior thyroid artery runs adjacent to what nerve?
recurrent laryngeal nerve (either anterior or posterior)
Venous drainage of superior vs. middle vs. inferior thyroid veins
superior + middle -> IJ vein
inferior -> innominate veins
Elevated calcitonin level >400, think…?
medullary thyroid cancer
Leukocytosis + normal TFTs in setting of tender, enlarged nodule… think?
acute suppurative thyroiditis
Mgmt acute suppurative thyroiditis
US-guided FNA w/ gram stain and Cx + Abx +/- drainage
MC bacteria acute suppurative thyroiditis
staph aureus + strep pyogenes
Most accurate and cost-effective assessment of thyroid nodules
FNA biopsy (PPV 97-99%)
MEN 1 malignancies
- pituitary adenoma
- parathyroid hyperplasia
- pancreatic tumor (MC gastrinoma)
MEN 2A malignancies
- parathyroid hyperplasia
- medullary thyroid CA
- pheo
MEN 2B maligancies
- medullary thyroid CA
- pheo
- mucosas neuromas + marfanoid body habitus
Sxs postpartum thyroiditis
thyrotoxicosis (anxiety, palpitations, insomnia) -> hypothyroidism (can be Tx levothyroxine for 6-9mo, tapered)
Suspicious sonographic features of thyroid nodule (5)
- hypoechoic
- microcalcifications
- increased central vascularity
- infiltrative margins
- taller than wider in transverse palne
Size indication for thyroid nodule to get FNA
> 1cm w/ suspicious US features OR >1.5cm wo features
If AUS or FLUS… mgmt?
if low malignancy risk -> repeat FNA
if w/ RF -> lobectomy
Fu for indeterminate FNA for follicular neoplasm + benign gene expression classifier (GEC)
repeat clinical exam + US at 1 year
Operative mgmt pt w/ medullary thyroid carcinoma on FNA, but negative cervical US for nodes
total thyroidectomy + central LN dissection (bc high rate CLN involvement and high US false-neg)
Who needs radioactive iodine Tx after total thyroidectomy?
- tumor 2-4cm
- vascular invasion
- anti TG Ab
- TG <5
- also allows following TG levels to assess recurrence
How to assess for recurrence of follicular thyroid CA?
follow TG levels
What size thyroid nodule requires evaluation with FNA?
- any solid thyroid nodule >/= 1.5cm size
- solid nodule >/= 1cm + suspicious features
Suspicious features of thyroid nodule on US
- hypoechoic
- microcalcifications
- infiltrative margins
- taller than wider in transverse plane
Tx after partial thyroidectomy for <1cm papillary thyroid CA
Thyroid hormone to suppress TSH + f/u with US
For which papillary thyroid carcinoma is partial thyroidectomy (lobectomy) okay?
- small, encapsulated (noninvasive) <1cm diameter
- age <45
- negative nodes
Damage to the external branch of the superior laryngeal nerve results in…?
affects voice pitch (motor innervation to cricothyroid muscle, which tilts larynx during speaking)
Damage to recurrent laryngeal nerve results in…?
airway compromise (innervates posterior cricoarytenoid muscles)
What size solid thyroid nodule requires evaluation with FNA?
> /= 1.5cm
Eval >/= 1cm only if + suspicious features
