Thyroid malignancies

1. THYROID MALIGNANCIES
Dr. M. Ziwa
General Surgeon - University Teaching Hospital
17th November, 2017.

2. Epidemiology
• Accounts for 1.5% of all cancers.
• The most common endocrine malignancy
(95% of all endocrine cancers).
• Higher in females than males (except for
anaplastic carcinoma). Ratio is approximately
2.5:1

3. Anatomy
• Largest endocrine
gland (20 - 25 g)
• Fills the
tracheoesophageal
space
• Overlies RLN bilaterally.
• Parathyroids lie at each
pole (usually)

4. Embryology

5. Histology

6. Physiology

8. Clinical manifestations
• Most are euthyroid, but with a thyroid nodule.
• Dysphagia, dyspnoea and voice hoarseness.
• Ipsilateral cervical lymphadenopathy may be
present.

9. Risk factors
1. Neck irradiation
The only well-established risk factor for differentiated thyroid
cancer . (* Read about the Chernobyl disaster)
2. Genetic factors
1. Papillary thyroid carcinoma may occur in several rare
inherited syndromes, including
i. Familial adenomatous polyposis
ii. Gardner's syndrome
iii. Cowden's disease
2. Medullary carcinoma in MEN syndrome

10. 3. Other risk factors
i. History of goiter
ii. family history of thyroid disease
iii. Female gender
iv. Asian race.

11. Diagnosis and management:
• Talk about the tripple assessment:
– Clinical
– Radiological
– Histopathological
• Then there are other investigations you can
do.

12. 1. Clinical
• Take a good history
• Do a good thyroid
examination.

13. 2. Radiological

14. Radioisotope scan
• Look for hot and cold
nodules.
• Cold nodules suggestive
of malignancy.

15. Whole body radioisotope scan

16. Others guided by the pt’s
presentation:

18. 3. Histopathology

20. Blood tests:
• Thyroid function tests (T3, T4, TSH)
• Serum calcium
• Thyroglobulin
• Calcitonin

21. Classification and Incidence of Thyroid
cancers
• Tumours of Follicular cell origin
– (a) Differentiated*
• Papillary 75%
• Follicular 10%
• Hurthle 5%
• In Zambia, Follicular is the most common
followed by Papillary. See dissertation [2013] by
Dr. M. Furkat on:
http://dspace.unza.zm:8080/xmlui/bitstream/handle/123456789/3261/Mirzakarimov.PDF?seque
nce=1

22. – (b) Undifferentiated
• Anaplastic 5%
• Tumours of Parafollicular cell origin
– Medullary 5%
• Others < 1%
(these include Lymphomas, teratomas,
sarcomas, metastases from other cancers)

23. Prognosis
• GAMES scoring (PAPILLARY & FOLLICULAR
CANCER)
– G Grade
– A Age of patient when tumor discovered
– M Metastases of the tumor (other than Neck
LN)
– E Extent of primary tumor
– S Size of tumor (>5 cm)
(AMES, GAMES, AGES)

25. Pathology of Thyroid cancer
• Differentiated thyroid cancer:
– Papillary spreads to nodes, excellent prognosis.
– Follicular spreads to bone, worse than Papillary.
Hurthle is variant of Follicular
*PapillarY (Yellow = Lymph)
FolliculaR (Red = Blood)

26. • Medullary
– Sporadic vs familial (MEN 2A)
– Total thyroidectomy is treatment.
• Anaplastic
– Aggressive and fatal
– Surgical role is biopsy only

27. Papillary
• The most common malignant thyroid tumor.
• Accounts for 70-80% of all cancers.
• Consists of Papillary, Follicular, Tall-cell,
Columnar Cell and Diffuse sclerosing.
• Women 2x > Men.
• Age Presentation 38-45.
• Accounts for 90% of radiation induced thyroid
cancer.

28. • Histologic: Psammoma bodies, intranuclear
groves and cytoplasmic inclusions
• Multicentric: 30-50%
• Spread via Lymphatics- propensity for cervical
node involvement.
• Invasion of adjacent structures and distant
mets uncommon.

29. Follicular
• 15-20% Of Thyroid Cancers
• “Well Differentiated”
• Usually Encapsulated
• More Common Among Older Patients
• Female > Male
• More Aggressive & Less Curable Than Papillary
• Hematologic Spread
• 60% 10 Year Survival
• Types: Overtly Vs Minimally Invasive Hurthle Cell

30. Hurthle cell neoplasm
• More aggressive than other differentiated thyroid
carcinomas (higher mets/lower survival rates)
• Decreased affinity for I 131
• Need to differentiate from benign/malignant
• 65% of tumors > 4cm are malignant
• If malignant, needs total thyroidectomy and I 131
with thyroglobulin assays
• Mets may be more sensitive to I131 than primary

31. Anaplastic
• Undifferentiated
• Rapidly growing, often inoperable
• Invade locally, metastasize both locally and
distantly
• Mean survival 6 months
• 5 year survival rate 7%

32. Lymphoma
• Rare, rapidly enlarging tumour
• Primary or secondary
• Seventh decade, 6:1 F/M ratio
• 5 year survival rate 75-80%, when confined to
thyroid

33. Treatment Guidelines
• The main treatment of papillary carcinoma of the
thyroid is surgical resection.
• For lesions <1 cm, there is general agreement in
the literature that lobectomy plus isthmectomy is
the appropriate treatment.
• For adults with lesions larger than 2 cm, a total
thyroidectomy is favored by most surgeons.
• Patients with history of exposure to ionizing
radiation of the head and neck should have total
thyroidectomy

34. Controversies in Treatment
Total vs Lobectomy
• Controversy exists about the use of total
thyroidectomy versus lobectomy and
isthmectomy in adults with a 1- to 2-cm
lesions.
• Role of Lymph node dissection also debated.