Thyroid Malignancy Flashcards
1
Q
Biosynthetic defect and dec iodine
A
Dec efficiency of thyroid hormone synthesis
Inc TSH
2
Q
Inc thyroid stimulating Ig
Upregulation of TSH receptor
Hyperthyroidism
A
Grave’s
3
Q
Lymphocytic infiltration
Release of immune system growth factor
Hypothyroidism
A
Hashimoto’s thyroiditis
4
Q
Grayscale sonographic features of thyroid cancer
A
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
5
Q
Most common malignancy of endocrine system
2x common in women than men
Male worse prognosis
A
Thyroid cancer
6
Q
Rf for thyroid ca
A
Head and neck irrad before 18 Ionizing radiation from fallout in childhood <20 >65 years Rapid enlarging mass Male gender Family hx of papillary
7
Q
Thyroid CA pathogenesis
A
Radiation
High TSH
Oncogenes
8
Q
Papillary thyroid ca alteration
Most common
Rearrangement
A
BRAF V600E
RET rearrangement/PTC/RAS/MAPK
9
Q
Follicular CA genetic alteration
A
PAX8-PPARy1 rearrangement
10
Q
Anaplastic Thyroid Ca genetic alteration
A
TERT
BRAF
CTNNB1
And
P53
11
Q
Loss of iodine uptake by tumor cell
A
BRAF mutation
12
Q
BRAF + thyroid ca signals
A
inc recurrence rate
13
Q
Medullary thyroid Ca is related to point mutation in
With hyperplasia of C cell
A
RET gene MEN 2
C cell produces calcitonin
14
Q
PTH increases
A
serum calcium
15
Q
Calcitonin dec
A
serum calcium
16
Q
80-85% of well differentiated thyroid malignancies are
Pathognomonic histologic finding
A
Papillary
Orphan annie eye Clear cell nuclei
17
Q
Multifocal
Invade locally within thyroid gland ane capsule and neck
Spreads via
A
Papillary thyroid ca
Lymlhatic but mets hematogenously bone and lung
Excellent prognosis
18
Q
Follicular TC histology
A
Hurthle cell
Marked vascular invasion
19
Q
Well differentiated thyroid ca tx
Small micropap thyroid T1a
A
Active surveillance
20
Q
Tumor >1cm T1b or larger tx
A
Surgical excision
21
Q
Tumor >4cm in presence of metastases
A
Neart total thyroidectomy
22
Q
Mainstay tx of well diff thyroid cancer
A
Levothyroxine supression of TSH
TARGET
low risk: 0.5-2.0
Intermediate 0.1-0.5
23
Q
After near total thyroidectomy, g of thyroid tissue remains in thyroid bed
Follow up with
A
<1 g
Postsurgical RAI eliminate residual gland
Contraindicated in pregnancy
24
Q
Thyroid ablation and tx
A
Iodine dep for 2 weeks Inc serum TSH >25? Pretx scan Ablation Whole body scan post ablation
25
Indications of RAI
```
Large tumors
More aggressive variants of papillary
Extrathyroidal invasion
Tumor vascular invasion
Presence of large volume LN mets
```
26
Surveillance thyroid test
Sensitive marker of residual recurrent thyroid cancer after ablation
Neck UTZ
External beam RT
Serum thyroglobulin tg
27
```
RAS
BRAF
RET
EGFR
VEGR
Angiogenesis
```
Kinase inhibitors
28
Doubling of PFS To 10.8 months among progressive metastatic thyroid cancer
sorafenib multikinase inhibitor
29
Poorly differentiated
Aggressive
Poor prognosis die within 6 mos
Anaplastic thyroid cancer
30
Anaplastic thyroid tx
Chemo: paclitaxel and anthracycline (daunorubicin, doxo)
EBRT
Use of checkpoint inhibition therapy
31
Background of Hashimoto’s thyroiditis
Rapidly expanding thyroid mass
Sensitive to RT
Thyroid lymphoma
32
Most common thyroid lymphoma
Diffuse large b cell lymphoma
33
5% of thyroid cancer
| 3 familial forms
Medullary thyroid
Men2A
Men2B - more aggressive
34
Non tender palpable solitary neck mass
| First dx
TSH
High
UTZ
Detectes on UTZ -> FNAB w cytology
TSH LOW
radionucleotide scanning
Hyperfuxn nodule
35
Thyroid cytology done by
Bethesda classification
36
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
37
Notorious for causinf hypo or hyper
Amiodarone
38
Most common location of cancer in esophagus
Middle third
39
Most common malignancy in iodine deficient region
Follicular TC
40
Calcitonin producing TC
Medullary thyroid
41
Carcinoma assoc with Hashimoto’s
Thyroid lymphoma
42
Thyroid lymphoma is thought to arise from
Chronic antigenic stimulation leading to proliferation of lymphoid tissue, somatic mutation, clonal proliferation, lymphoma
43
Thyroid lymphoma is thought to arise from
Hashimoto’s thyroiditis
| as rapidly expanding thyroid mass
44
Most cases of thyroid carcinoma present with
a thyroid nodule
45
CLADs in thyroid carcinoma signify
local progression
46
Most common metastases of thyroid cancer
Lung
| Bone
47
Rapidly enlarging thyroid mass
| Regional or distant metasteses
Anaplastic TC
48
MTC may present with paraneoplastic secretion of ectopic
adrenocorticotropic hormone ACTH
49
Most common symptoms of Medullary TC
Diarrhea
Flushing
due to calcitonin
50
Diagnosis made on basis of cytologic features from FNA or surgical pathology
Multifocal
Invade locally within thyroid gland and through thyroid capsule into adjacent structures in the neck
Grows slowly
Papillary TC
51
PTC has propensity to spread via
Lymphatics
but may spread hematogenously particularly to bone and lung
significant burden of pulmonary metastases may accumulate sometimes with few symptoms
52
Diagnosis is made on the bases of characteristic cytologic features on specimens from SURGICAL PATHOLOY
Difficult to diagnose by FNA nor cytopathology nor frozen section
Follicular TC
53
Distinction between benign and malignant Follicular TC rests on evidence of
invasion into vessels, nerves, capsules and adjacent structures
54
Follicular TC tends to spread
Hematogenously to bone, lung and CNS
55
Diagnosis is made on the basis of cytologic features on specimen from FNA or surgical pathology
Poorly differentiated and aggressive arising from differentiated thyroid carcinoma due to V600E alteration in BRAF as with papillary
Uptake of radioiodine negligible
Anaplastic TC
56
Definitive diagnosis made on the basis of cytologic features on specimens from FNA or surgical pathology
High serum calctonin and CEA can be indicative
Radioiodine scans not helpful since they do not accumulate radioiodine
Medullary TC
57
Routine measurement of calcitonin is not recommended to detect MTC or in a patient with thyroid nodule
and should be tested instead only in persons presenting with
Diarrhea
| Flushing
58
Diagnosis of primary thyroid lymphoma rests on demonstration of
sheets of lymphoid cells in FNA
| core biopsy specimen
59
Can aid distinction of lymphoma from small cell lung cancer or Anaplastic TC
Immunophenotyping
60
Most common Primary Thyroid Lymphoma
Diffuse Large Cell Non-Hodgkin Lymphoma
61
Reed Sternberg Cells
Hodgkins B Lymphoma
62
Starry sky appearance
Burkitt lymphoma
63
TSH level in 95% of TC patients
Normal
64
Marker for residual, recurrent or metastatic disease in WELL-DIFFERENTIATED TC
in patients with complete excision/ablation
Thyroglobulin Tg
Sensitivity of Tg increases when TSH is elevated
Interference of 20% can invalidate serum Tg assay
65
Tg measurement suggests persistent ir recurrent thyroid carcinoma
>2 ng/mL
66
Tg level is increased in most metastatic
Papillary
| Follicular
67
Serum calcitonin level associated with cancer
500-2000 pg/mL
CEA
68
Should be performed in sporadic cases of MTC to evaluate possibility of MEN2
RET mutational analysis
69
Useful to aid in accurate needle placement in FNA
Used preoperatively in pathologically confirmed thyroid cancer to identify potential metastatic nodes and assist in planning the appropriate nodal dissection during surgical resection
Also useful to monitor for/identify sites of recurrent disease
Ultrasonography of neck
70
Radioactive iodine uptake is significant in these types of TC in areas of residual or recurrent disease including bone and soft-tissue metastases
Papillary
| Follicular TC
71
Used to identify sites of distant metastases
18-Fluoro-deoxyglucose FDG positron emission tomography PET
72
Good sensitivity and specificity
| Accurate for detecting Papillary TC
FNA
73
Nondiagnostic biopsies occur because
Fibrotic reaction with few cells available for aspiration
Cyst in which cellular components reside along cyst margin
Nodule too small for aspiration
74
Additional preop diagnositc imaging after positive FNA
Chest radiography
Preoperative neck ultrasonography
CT or MRI of the neck, for fixed or substernal lesions
Evaluation of vocal cord mobility
75
Papillary TC variant
Pure papillary
Follicular
Diffuse sclerosing
Tall-cell, columnar-cell
76
Folicullar TC variant
Minimally invasive
Widely invasive
Hurthle Cell Carcinoma (oncocytic)
Insular carcinoma
77
T1 staging
= 2 cm
| limited to thyroid
78
T2 staging
2-4cm
| limited to thyroid
79
T3 staging
>4cm limited to thyroid or minimal extrathyroidal extension
80
T4a
any size extending beyong capsule to soft tissue, larynx, trachea, esophagus or recurrent laryngeal nerve
81
T4b
Tumor invades prevertebral fascia
Encases carotid artery
Mediastinal vessels
82
N1
Regional lymph node metastasis
83
N1a
Metastasis to level VI (pre, paratracheal, Delphian)
84
N1b
Metastasis to unilateral, bilateral or contralateral cervical or superior mediastinal lymph nodes
85
Stage grouping for PTC or FTC in <45
Stage I
Stage II
Any T, N, M0
Any T, N, M1
86
Stage grouping for PTC or FTC >/= 45 or MTC any age
Stage IVc
Any T, Any N, M1
only M1
87
Stage grouping for anaplastic carcinoma
All stages are considered stage IV
88
Primary mode of therapy for well-differentiated thyroid carcinoma and MTC
Total thyroidectomy
89
Total thyroidectomy is indicated as primary mode of treatment for well differentiated TC because
Removes primary lesion
Allows accurate histologic diagnosis and staging
Allows assessment of lymph node involvement and spread
Allows post-therapeutic surveillance using Tg as tumor marker
90
Thyroidectomy + Postsurgical radioablation is performed in
```
Age <15 >45
History of radiation
Known distant metastases
Bilateral disease
Extrathyroidal invasion
Tumor >4cm
Cervical lymph node metastases
Family history of thyroid cancer
```
91
Used for postsurgical ablation of residual thyroid tissue
Treatment of residual or recurrent TC
Reduction in recurrence rates
Improved monitoring with whole-body scanning and serial Tg
Radioiodine treatment
Most stage 1 PTC primary tumor <1.5 can be managed safely with thyroxine supression
92
Patients who generally require thyroid ablation and radioiodine treatment
Larger papillary carcinomas adjacent lymph node involvement or extrathyroidal invasion
FTC
Evidence of metastases
93
Strategy for postop radioiodine remnant ablation
2 weeks of liothyronine T3 25ug and then
Complete thyroid withdrawal for 2 weeks
Avoid pretreatment of scanning dise 131I to avoid stunning thyroid cells
Proceed directly to ablation unless suspicion that anount of residual tissue will alter therapy
94
To increase radioiodine uptake patient must be placed on this diet
Low iodine <50 ug/d urinary iodine
Alternate strategy: Recombinant human TSH (rhTSH) to enhance 131 uptake for post surgical ablation
95
Used to treat specific metastatic lesions when they cause bone pain or threaten neurologic injury (vertebral metastases)
External-beam radiotherapy
96
Anaplastic TC therapy
Multimodal
Chemotherapy: cisplatin, bleomycin, 5-fu, cyclophosphamide
EBRT if responsive
97
Thyroid lymhpoma is highly sensitive to
External-beam radiation
Avoid surgical resection
98
Primary mode of therapy in MTC
Radioiodine treatment not indicated
Total thyroidectomy
EBRT for extensive local metastasis
Chemotherapy: doxorubicin, vincristine, cyclophosphamide, dacarbazine
99
Monitoring of Well-differentiated TC
TSH supression (0.1-0.5 mU/L)
If high risk of recurrence or metastatic, complete supression <0.1
FT4 monitored to avoid excessive treatment
100
Monitoring for recurrence 2
| Primary technique
Imaging 131I whole body scanning and/or thyroid ultrasonography
Serum Tg
101
Initial whole body scan following post therapy scan should be performed after how long post surgery/thyroid ablation
6-12 months
102
For patients at low risk of recurrence Tg <2 ng/ml this may be used as an alternative to thyroid hormone withdrawal to stimulate Tg 131I uptake after ablation
Avoids symptoms of hypothyroidism and risk of prolonged TSH stimulated growth tumor
Recombinant human TSH
103
Residual disease or metastases is treated with
Therapeutic 131I
Continue surveillance measures if there is no apparent disease
104
PE should be done in differentiated TC
every 3-6 months for 2 years
| annually if disease-free
105
TSH and Tg antibodies in differentiated TC should be done
at 6 and 12 months
| Anually if disease free
106
Radioiodine scan in differentiated thyroid carcinoma every
12 months until 1 negative scan if undergone total thyroidectomy and ablation
107
Surveillance protocol for differentiated TC
Periodic neck UTS and chest radiograph
Additional FDG PET or CT if Tg >10 ng/mL if 131I are negative and stimulated Tg level is >2-5 ng/mL
Consider rhTSh stimulated Tg in low risk patients with negative neck ultrasonography
108
MTC surveillance
Annual measurement of basal calcitonin and CEA
Periodic neck ultrasonography
Ocreotide scanning to localize
109
Complications specific to MTC
Secretion of serotonin and prostaglandin causing Flushing, diarrhea
Secretion of ACTH or CRH
Cushing’s
110
Complications of 131I ablation
Sialodenitis
Radiation thyroiditis
Nausea
Dysgeusia and metallic taste sensation
Infertility and chromosomal abnormalities in offspring occur very rarely after exposure to high doses
Radiation fibrosis or lung (very high cumulative doses)
111
<20 years >45 years
| Prognosis
Worse
112
Male sex
| Prognosis
Worse
113
Mortality is markedly increased in stage IV disease (1%)
Papillary
114
Poor prognostic factors in Follicular TC
```
Distant metastases
Age >50 years
Primary tumor size >4 cm
Hurthle cell histology
Presence of marked vascular invasion
```
115
Medullary TC may be prevented in patients known to harbor a germline mutation of
RET protooncogene MEN2
By early prophylactic thyroidectomy
Men2A 10 years
Men2B 4 years
