NECROSIS FOR MBBS FIRST YEAR STUDENTS MADE EASY.pptx
Thyroid cancers
1. Thyroid cancers
•Infrequent cancers-3% of all cancers
•Benign diseases common
•Requires multidisciplinary action
•Women are affected 3 times more than
men
•Peak incidence 30-40yrs
3. Etiology & Risk factors
• Arise from 2 types of cells
• Follicular cells makes papillary,follicular &
anaplastic
• Parafollicular C cells makes medullary
• Radiation exposure & Hashimotos
thyroiditis are risk factors for papillary ca.
• Low dietary iodine is riskfactor for follicular
& anaplastic
4. History
• Present as Painless palpable thyroid
nodule
• Nodules are present in 4-7% of population
but most are benign,5% are mlignant
• Peak incidence occurs between age of 30-
50yrs
• More common in females
• Malignant nodules are usually painless
• Hoarseness suggests malignancy-nerve
involvement
6. Examination
• Thyroid gland
• Soft tissues of neck
• Tenderness?
• Consistency(Hard/firm/soft) mobility(fixed
or not)
• Laryngoscopy if hoarseness presents
7. GOAL is
• To differentiate malignant from benign
nodules
• Determine which patient require
intervention / who can be monitered
• Avoid unnecessary surgery
8. FNAC
•First intervention in evaluation of nodule
•Inexpensive,easy,few complications
•Needs a good cytopathologist
•Four types of results-benign-69%
mallignant-4%
indeterminate-10%
nondiagnostic-17%
Sensitivity-83%,specificity-91%
9. • If nondiagnostic-repeat
• If benign-followup
• If malignant-surgery
• If indeterminate-surgery
10. Lab
• TSH-to know the hyper/hypo thyroidism,
not helpful in malignancy
• Sr.Thyroglobulin as a tumour marker in
post op to assess
• Calcitonin for medullary ca.
11. Imaging
• U/S-to differenciate solid & cystic
lesions,for FNA accuracy & for monitoring
of benign lesions
• Scans-determine function of nodule
• Carcinoma can not be ruled out based on
scans as 4%of hot nodules also malignant
• CT/MRI not used routinely
12. Papillary cancer
• Most common(80%)
• Women-3 tims more common
• 30-40yrs of age
• Risk factors-radiation exposure in
childhood, Hashimotos thyroiditis
• Slow growing,TSH sensitive,take up
iodine,TSH stimulation produces Tg
response
14. • Loacl invasion through capsule, invading
trachea, nerve causing dyspnea,
hoarseness
• Propensity to spread to the cervical
lymphnodes,clinically evident in 1/3 of
patients-mostly central compartment
• Distal spread to lung & bones
15. Follicular carcinoma
• Second most common(10%)
• Iodine deficient areas
• 3 times more in Women
• Presents more in advanced stage than
papillary
• Late 40’s
• Also TSH sensitive, takes up iodine,
produces Tg
16. pathology
• Round, encapsulated, cystic
changes,fibrosis, haemorrhages
• Microscopically neoplastic follicular cells
• Differentiated by follicular adenoma by
capsular invasion & angioinvasion
• Cannot reliably diagnose based on FNA
17. • Local invasion is similar to papillary cancer
with same presentation
• Cervical metastases are uncommon
• Distant metastases is significantly
higher(20%),with lung & bone as most
common sites
18. Treatment & Prognosis
• Total thyroidectomy with lymphnode
dissection if positive nodes present is
mainstay of treatment for differentiated
thyroid cancers
• Post surgery radioiodine scan for
detection & ablation of remnant thyroid
tissue in neck or in metastatic sites
19. Post operative radioiodine &
Ablation
• I-131 targets residual thyroid tissue &
tumour after thyroidectomy
• First given in diagnostic dose to detect &
then in therepeutic dose to ablate it
• Hypothyroid state (TSH>30mIU/l) is
required for better iodine uptake for that
routine eltroxin supplimentation after
surgery is to be avoided
20. Thyroid supression therapy
• Low TSH levels reduce the tumour growth
rates & recurrence rates,so after surgery &
radioablation patients should be
maintained on thyroxin
• Most recommended TSH level is
<0.1mIU/l
• Followup 6monthly with thyroglobulin level
& scans are recommended
21. Prognosis
• Age at diagnosis-Cancer related deaths
are more common if patient is older than
40yrs
• Recurrences are common in patients
diagnosed at <20yrs / >60yrs of age
• Men are at double risk to die
• Tumors of >4cm have high recurrence
rate & deaths
22. • 30yr cancer related death rate is 6% for
papillary & 15% for follicular cancer
• Local invasion portends poorer prognosis
• LN metastases is not important for
prognosis
• Distant metastases associated with 68fold
increase in disease specific death rate
23. Hurthle cell carcinoma
• A Variant of follicular cancer,also known as
oncocytic carcinoma
• 5yr survival-50%
• More common in females and in 5th decade of life
• Same clinical presentation as follicular ca.
• Can not be diagnosed on FNA
• Does not take up Iodine, so treat aggressively
• Radio iodine, Thyroid suppression does not work
24. Medullary carcinoma
• 5% female preponderance
• 75% sporadically,25% familial.
• In familial cases, the lesions are usually all
over the gland whereas in sporadic they
are not
• Associated with MEN 2a,2b & FMTC
syndromes
25. • MEN 2a - also known as Sipple syndrome
MTC, pheochromacytoma,
pitutory,parathyroid adenomas
• MEN 2b – MTC, pheochromacytoma,
ganglionomas/neuromas,
morphanoid habitus
• FMTC – only MTC
• MTC in familial cases are more
aggressive, presents in younger age, with
rapid growth & metastases
• Whereas in sporadic cases presents as
painless nodule/symptoms of invasion
26. Biochemical test in MTC
• Calcitonin levels are used as tumour marker for
MTC in post op to detect recurrence
• Stimulating Calcitonin release with IV
pentagastrin increases sensitivity of test- first
measures baseline calcitonin, then gives
pentagastrin, then measure calcitonin serially at
1.5 & 5min intervals
• Genetic test to detect RET gene for screening
• Histologically test for Calcitonin,CEA
27. Treatment for MTC
• Total thyroidectomy
• Lymphnode dissection of level 6
• Parathyroid reimplantation if necessary
• Prophylactic thyroidectomy in children with
MEN 2a,b (>90% penetrance)
• Survielance with Calcitonin, CEA
• Does not take up iodine, so no radioiodine
• Prognosis-10yr survival rate is 65%
28. Anaplastic cancer
• Bad
• Aggressive, much invasive
• Surgery is not indicated
• Radio/chemotherapy
29. Indications for total thyroidectomy
• Well differentiated thyroid cancer
• Medullary thyroid cancer
• Sarcoma of thyroid
• Lymphoma of thyroid
• Obstructive goitre