Thyroid Malignancies

1. Thyroid Malignancies
By: Dr. Noshirwan P. Gazder

2. Epidemiology
• Commonest endocrine malignancy.
• 1% of all malignancies.
• 0.5-1 per 100000.
• Good prognosis.
• Annual Incidence is 3.7 per 100,000.
• Sex Ratio is 3:1 (Female:Male).
• Can occur at any age group.

3. Thyroid Neoplasms
• Benign.
• Malignant.

4. Benign Thyroid Neoplasms
• Follicular Adenoma.
• Colloid Nodule

5. Malignant Thyroid Neoplasms
Dunhill Classification:
• Differentiated:
1. Papillary carcinoma (60%).
2. Follicular carcinoma (17%).
• Undifferentiated:
1. Anaplastic carcinoma (13%).
2. Medullary carcinoma (6%).
3. Malignant lymphoma (4%).
4. Secondaries in thyroid (rare) – From colon, kidney etc.

6. Aetiology of Thyroid Malignancy
• Exposure to radiation in childhood.
• Victims of nuclear disaster.
• Family history (first degree relatives).
• Pre-existing multinodular goitre, can turn into follicular carcinoma of
the thyroid.
• Medullary cancer thyroid syndromes (MEN2A/MEN2B).
• Hashimoto thyroiditis can turn into a thyroid lymphoma.

7. Presentation
• Presence of a thyroid nodule is the most common incidental finding
There is increased suspicion of malignancy when :
• Rapid growth.
• Firmness.
• Vocal cord paralysis.
• Dysphagia.
• Cervical lymphadenopathy.

8. Advance cases may present with :
• Airway compromise.
• Hoarseness of voice.
• Pain.
• Weight loss.
• Respiratory distress.

10. Papillary Carcinoma
• It is 60% common.
• Common in females and younger
age group.
• Aetiology: Radiation either
external or radioactive iodine
therapy.
• TSH levels in the blood of these
patients are high and so it is alos
known as a “hormone
dependent tumour”.

11. • Gross: It can be a soft, firm, hard or cystic mass. It can be solitary or
multinodular. It contains brownish black fluid.
• Microscopy: It shows cystic spaces, papillary projections with
“Psammoma bodies”, malignant cells with “Orphan Annie eye” nuclei
(intranuclear cytoplasmic inclusions).

13. Spread
• It is a slowly progressive and less aggressive tumour.
• It spreads within the gland through intrathyroidal lymphatics to the
other lobe(Intrathyroidal disease) or it comes out of the capsule and
spreads to cervical lymph nodes.
• Blood borne metastases is unusual unless the tumor is extra-thyroidal

14. Clinical Features
• Can present as a soft or hard or firm, solid or cystic, solitary or
multinodular thyroid swelling.
• Compression features are uncommon in papillary carcinoma.
• Often discrete lymph nodes in the neck (40%) are palpable.

15. Diagnosis
• FNAC of thyroid nodule and lymph node.
• Radioisotope scan will show a cold nodule.
• TSH level in the blood is higher.
• Plain X-ray neck will show fine calcifications.
• U/S neck or CT scan neck (better) to identify nonpalpable nodes in
neck.

16. Treatment
If the mass is <1.5 cm and there is no history of neck radiation exposure
then:
• Thyroid Lobectomy.
• Total or near total thyroidectomy, may be performed.
If the mass is ≥1.5 cm and there is history of neck radiation exposure or if
the mass is bilateral then:
• Total thyroidectomy is performed
• Modified radical neck dissection type III is required if lymph nodes are
involved.
• Extrathyroidal type also responds well to radioactive Iodine-131 therapy.

17. Prognosis

18. Follicular Carcinoma
• It is 17% common.
• It is common in females.
• It can occur in a pre-existing multinodular goitre.
It can be either:
• Noninvasive—Blood spread not common.
• Invasive—Blood spread common.

19. Spread
• It is a more aggressive tumour.
• It spreads mainly through blood into the bones, lungs, liver.
• Bone secondaries are typically vascular, warm, pulsatile, localised,
commonly in skull, long bones, ribs.
• It can also spread to lymph nodes in the neck occasionally (10%).

21. Clinical Features
• Swelling in the neck, firm or hard and nodular.
• Tracheal compression and stridor.
• Dyspnoea, haemoptysis, chest pain when there are lung secondaries.
• Recurrent laryngeal nerve involvement causes hoarseness of voice.
• Positive Berry’s sign signifies advanced malignancy.
• Pulsatile secondaries in the skull and long bones.

23. Investigations
• Most often FNAC is inconclusive as it is difficult to differentiate it from
follicular adenoma , because capsular invasion/vascular invasion,
which are the main features in follicular carcinoma, cannot be
detected by FNAC.
• Frozen section biopsy is very useful.
• U/S abdomen, chest X-ray, X-ray bones are also required.
• Trucut biopsy gives tissue diagnosis, but danger of haemorrhage and
injury to vital structures like the trachea, blood vessels or the
recurrent laryngeal nerve is likely.

24. Treatment
• Total thyroidectomy and median lymph node dissection
• Modified neck dissection, if lateral cervical nodes are positive.
Follow up:
• It is by Iodine-123 scan done at regular intervals (6 months) to look
for secondaries.
• U/S neck or MRI neck to identify early relapse.
Further treatment: If secondaries are detected therapeutic dose
Iodione-131 is given orally. L-thyroxin has to be stopped 6 weeks prior
to RT, then required dose of Ra I131 is given (50-150 m curie.)
• Secondaries in bone are treated by external radiotherapy.

26. Anaplastic Carcinoma
• It occurs in elderly.
• It is a very aggressive tumour of short duration, presents with a
swelling in thyroid region which is rapidly progressive causing:
i. Stridor and hoarseness of voice due to tracheal obstruction.
ii. Dysphagia.
iii. Fixity to the skin.
iv. Positive Berry’s sign.

28. • The swelling is hard, with involvement of the isthmus and lateral
lobes.
• FNAC is diagnostic.
• Tracheostomy may be performed to relieve respiratory obstruction
temporarily.
• Treatment is external radiotherapy, as usually thyroidectomy is not
possible.
• Adriamycin can be used as a chemotherapy drug.
• Prognosis is poor.

29. Medullary Carcinoma
• It arises from the parafollicular ‘C’ cells.
• It contains characteristic ‘amyloid stroma’ where in malignant cells
are dispersed.
• Immunohistochemistry reveals calcitonin in amyloid.
• It spreads mainly to lymph nodes (60%).
• 30% patients also complain of diarrhea.
• Medullary carcinoma may occur in combination with adrenal
phaeochromocytoma and hyperparathyroidism in the syndrome
known as multiple endocrine neoplasia type 2A (MEN-2A).

30. • The prognosis is variable and depends on the stage at diagnosis.
• Any nodal involvement virtually eliminates the prospect of cure
• Even small tumours confined to the thyroid gland may have spread by
the time of diagnosis, particularly in the case of familial cancers.

31. • When medullary carcinoma is diagnosed, staging of the neck and
chest should be performed.
• For those patients with disease confined to the thyroid, total
thyroidectomy is recommended to remove all C cells.
• In addition, elective dissection of the central neck nodes is also
performed to optimise the chance of cure.
• If there is evidence of nodal metastases, cure is unlikely.

33. References
• Bailey and Love Short practice of Surgery.
• SRB’s Manual of Surgery.

34. Thank You