Thyroid Malignancy Flashcards
Biosynthetic defect and dec iodine
Dec efficiency of thyroid hormone synthesis
Inc TSH
Inc thyroid stimulating Ig
Upregulation of TSH receptor
Hyperthyroidism
Grave’s
Lymphocytic infiltration
Release of immune system growth factor
Hypothyroidism
Hashimoto’s thyroiditis
Grayscale sonographic features of thyroid cancer
Hypoechoic compared with surrounding thyroid 81% M sensitivity
Hypoechogenicity (94% high specificity)
Microcalcification
Irregular microlobulated margin
Solid consistency (highest median sensitivity 78-91)
Taller than wide shape on transverse view
Most common malignancy of endocrine system
2x common in women than men
Male worse prognosis
Thyroid cancer
Rf for thyroid ca
Head and neck irrad before 18 Ionizing radiation from fallout in childhood <20 >65 years Rapid enlarging mass Male gender Family hx of papillary
Thyroid CA pathogenesis
Radiation
High TSH
Oncogenes
Papillary thyroid ca alteration
Most common
Rearrangement
BRAF V600E
RET rearrangement/PTC/RAS/MAPK
Follicular CA genetic alteration
PAX8-PPARy1 rearrangement
Anaplastic Thyroid Ca genetic alteration
TERT
BRAF
CTNNB1
And
P53
Loss of iodine uptake by tumor cell
BRAF mutation
BRAF + thyroid ca signals
inc recurrence rate
Medullary thyroid Ca is related to point mutation in
With hyperplasia of C cell
RET gene MEN 2
C cell produces calcitonin
PTH increases
serum calcium
Calcitonin dec
serum calcium
80-85% of well differentiated thyroid malignancies are
Pathognomonic histologic finding
Papillary
Orphan annie eye Clear cell nuclei
Multifocal
Invade locally within thyroid gland ane capsule and neck
Spreads via
Papillary thyroid ca
Lymlhatic but mets hematogenously bone and lung
Excellent prognosis
Follicular TC histology
Hurthle cell
Marked vascular invasion
Well differentiated thyroid ca tx
Small micropap thyroid T1a
Active surveillance
Tumor >1cm T1b or larger tx
Surgical excision
Tumor >4cm in presence of metastases
Neart total thyroidectomy
Mainstay tx of well diff thyroid cancer
Levothyroxine supression of TSH
TARGET
low risk: 0.5-2.0
Intermediate 0.1-0.5
After near total thyroidectomy, g of thyroid tissue remains in thyroid bed
Follow up with
<1 g
Postsurgical RAI eliminate residual gland
Contraindicated in pregnancy
Thyroid ablation and tx
Iodine dep for 2 weeks Inc serum TSH >25? Pretx scan Ablation Whole body scan post ablation
Indications of RAI
Large tumors More aggressive variants of papillary Extrathyroidal invasion Tumor vascular invasion Presence of large volume LN mets
Surveillance thyroid test
Sensitive marker of residual recurrent thyroid cancer after ablation
Neck UTZ
External beam RT
Serum thyroglobulin tg
RAS BRAF RET EGFR VEGR Angiogenesis
Kinase inhibitors
Doubling of PFS To 10.8 months among progressive metastatic thyroid cancer
sorafenib multikinase inhibitor
Poorly differentiated
Aggressive
Poor prognosis die within 6 mos
Anaplastic thyroid cancer
Anaplastic thyroid tx
Chemo: paclitaxel and anthracycline (daunorubicin, doxo)
EBRT
Use of checkpoint inhibition therapy
Background of Hashimoto’s thyroiditis
Rapidly expanding thyroid mass
Sensitive to RT
Thyroid lymphoma
Most common thyroid lymphoma
Diffuse large b cell lymphoma
5% of thyroid cancer
3 familial forms
Medullary thyroid
Men2A
Men2B - more aggressive
Non tender palpable solitary neck mass
First dx
TSH
High
UTZ
Detectes on UTZ -> FNAB w cytology
TSH LOW
radionucleotide scanning
Hyperfuxn nodule
Thyroid cytology done by
Bethesda classification
Hyperthyroidism from single hyperfunctioning nodule
RAI scanning shows hot nodule with suppression of rest of thyroid gland
Rarely malignant
Smaller nodule - antithyroid med and RAI
lobectomy and isthmusectomy - larger nodule
Plummer’s disease
Toxic adenoma
Notorious for causinf hypo or hyper
Amiodarone
Most common location of cancer in esophagus
Middle third
Most common malignancy in iodine deficient region
Follicular TC
Calcitonin producing TC
Medullary thyroid
Carcinoma assoc with Hashimoto’s
Thyroid lymphoma
Thyroid lymphoma is thought to arise from
Chronic antigenic stimulation leading to proliferation of lymphoid tissue, somatic mutation, clonal proliferation, lymphoma
Thyroid lymphoma is thought to arise from
Hashimoto’s thyroiditis
as rapidly expanding thyroid mass
Most cases of thyroid carcinoma present with
a thyroid nodule
CLADs in thyroid carcinoma signify
local progression
Most common metastases of thyroid cancer
Lung
Bone