1) Differentiated thyroid cancer consists of papillary and follicular thyroid carcinomas which together make up approximately 90% of thyroid cancers. 2) Papillary thyroid cancer is the most common type and typically presents as a solitary thyroid nodule. It has characteristic nuclear features on microscopy. 3) Follicular thyroid carcinoma accounts for about 15% of cases and has a higher risk of vascular invasion and distant metastasis compared to papillary carcinoma.

1. MANAGEMENT OF
DIFFERENTIATED THYROID
CANCER
DR. NIPPUN BHAMRAH
DEPARTMENT OF ENT
GMC AMRITSAR

2. THYROID GLAND (BRIEF ANATOMY)
• Butterfly shaped gland, largest endocrine organ in the
body.
• Weighs 15-20 g in adulthood.
• Highly vascular, reddish brown, bi-lobed structure with
each lobe joined together by a narrow isthmus.
• Each lobe is pear shaped, measuring approximately
5cm in length, 3cm in width and 1.5 cm in depth.
• The more rounded Lower pole extends down to the
level of 4th or 5th tracheal ring. The isthmus overlies
the 2nd to 4th tracheal rings.
• Thyroid gland, together with the oesophagus and
trachea is invested in a Visceral layer of deep fascia
known as the Pretracheal fascia.

3. MICROSCOPIC ANATOMY
• Made up of multiple lobules supplied by a
lobular artery. A thyroid lobule consists of 20-
40 follicles which are spherical in shape and
0.02-0.9mm in diameter.
• Each follicle is an aggregate of follicular cells
which are one cell thick surrounding a central
pool of viscous colloid. When the gland is
relatively inactive, the cells are flattened and
the colloid is abundant.
• On prolonged and excessive TSH stimulation,
the follicular cells become hypertrophied and
hyperplastic and adopt a columnar shape.
• Scattered in the stroma are some
embryologically distinct cells known as
parafollicular cells/C cells. They secrete
calcitonin in response to elevated serum
levels of calcium or gastrin.

4. WHO CLASSIFICATION OF TUMOURS OF THYROID GLAND.

5. INTRODUCTION
• Differentiated thyroid cancer consists of a group of malignant tumors derived from the thyroid
follicular cells.
• Thyroid cancer is uncommon, making up around 1 percent of all cancers and DTCs (including
papillary and follicular adenocarcinomas) make up around 90 percent of all thyroid
malignancies.
• The incidence of DTC is higher in women, older patients and those with a family history or
previous radiation exposure.
• By far, the most common presentation of DTC is as a solitary thyroid nodule.
• However, papillary and follicular thyroid cancers may present with locally invasive symptoms
and signs such as laryngeal nerve palsy, dysphagia or airway compromise, evidence of
metastatic disease with palpable lymph nodes or distant spread to the bones producing a
pathological fracture.
• Thyroid nodules are common and occur in approximately 5 percent of women and 1 percent of
men living in iodine sufficient areas.

6. THYROID CANCERS

7. PATHOLOGY AND CLASSIFICATION OF DTC
• Differentiated carcinomas derived from thyroid follicular cells can be separated into two main
categories.
• The most common is papillary thyroid cancer, which makes up to 75-80 percent of all thyroid
malignancies.
• The second most common type of DTC is follicular thyroid carcinoma, which accounts for
approximately 10 percent of all thyroid cancers. They are more common in women and
present usually in the older age group.

8. PAPILLARY THYROID CANCER
• Papillary thyroid cancer is a malignant epithelial tumor
showing follicular cell differentiation with characteristic
nuclear features. It accounts for approximately 80 percent
of all thyroid cancers and is also the commonest
paediatric thyroid malignancy.
• In adults it typically occurs between the ages of 20-50
years with a female preponderance with less pronounced
gender bias in patients over 50 years of age.
• It normally carries an excellent prognosis, especially in
younger patients.
• In areas of adequate dietary iodine, PTC usually presents
as a solitary thyroid nodule.
• In regions of iodine insufficiency multinodular goitre is
common and PTC can present as a more prominent or
distinctive nodule.
• It has propensity for lymphatogenous spread, initially to
locoregional lymph nodes.

9. PAPILLARY THYROID CANCER
• Prototypically, it is invasive with irregular outline and
either a scirrhous or granular, gritty texture often with
multiloculated cystic change and colloid contents.
• The encapsulated follicular variant of PTC is usually well
circumscribed possessing a solid, fleshy cut- surface,
closely resembling an adenoma.
• The principle DEFINING FEATURE of PTC is its nuclear
morphology by light microscopy.
• There is at least focal nucleomegaly, nuclear crowding
and nuclear overlap (Basket of eggs).
• Homogenization of karyoplasm (ground glass nuclei)
with margination of chromatin (Orphan Annie Nuclei) is
characteristic, but not pathognomonic.

10. MICROSCOPIC FEATURES OF PTC
1. Orphan annie-eye nucleus due to
nuclear crowding, nuclear overlap
(basket of eggs) and optically clear
karyoplasm.
2. Intranuclear ctoplasmic inclusions
(Pseudo inclusions)
3. Nuclear grooving (coffee beans)

11. PAPILLARY THYROID CANCER (MICROSCOPY-
PSAMMOMA BODIES)
• Psammoma bodies (laminated
calcospherites) are present in roughly
50% of PTCs histologically, less
frequently on FNAC and are
pathognomonic.
• They represent mineralized stromal
cores and therefore must be stromal in
location.

12. PAPILLARY THYROID CANCER (MICROSCOPY-
PSAMMOMA BODIES)

13. HISTOLOGICAL VARIANTS OF PTC
• PTC (Papillary/follicular/mixed pattern)
• Follicular variant PTC
• Tall cell variant PTC
• Cribriform PTC
• Columnar cell variant PTC
• Papillary microcarcinoma
• Solid variant PTC
• Diffuse sclerosing variant PTC

14. HISTOLOGICAL VARIANTS OF PTC
• TALL CELL VARIANT OF PTC
• These tumors tend to present in older patients
(greater than 50 years of age) and are generally
more bulky in size than conventional PTCs,
often with extension beyond the thyroid
capsule. The majority of cases present with
metastases to the lymph nodes or even distant
metastases.
• Showing columnar cells, their height being at
least three times greater than their width, and
they are not hyperstratified, in contradistinction
to columnar cell carcinoma.
• This is the most aggressive variant among all
the types.

15. HISTOLOGICAL VARIANTS OF PTC
COLUMNAR CELL VARIANT (CCV)
Clinical presentation: These tumors are rare. They are
frequently symptomatic, or present as an enlarging neck
mass ( in which there is invasion into the laryngeal soft
tissue and cartilage) and are clinically indistinguishable
from classical PTC.
• A rare and aggressive variant of PTC, CCV has been
associated with widespread metastasis and poor
prognoses, particularly if presenting as an infiltrating
mass.ge

16. HISTOLOGICAL VARIANTS OF PTC
SOLID VARIANT OF PTC
• The small cell nests demonstrate the distinctive
nuclear features.

17. HISTOLOGICAL VARIANTS OF PTC

18. FOLLICULAR THYROID CANCER
• About 15% of all thyroid cancer cases are follicular thyroid cancer. Follicular carcinoma is
considered more malignant (aggressive) than papillary carcinoma.
• Follicular thyroid cancer occurs in a slightly older age group than papillary thyroid cancer and
is also less common in children. In contrast to papillary cancer, it occurs only rarely after
radiation therapy.
• Mortality is related to the degree of vascular invasion. Age is a very important factor in terms
of prognosis. Patients older than 40 years old have a more aggressive disease and typically
the tumor does not concentrate iodine as well as in younger patients. Vascular invasion is
characteristic for follicular carcinoma and therefore distant metastasis is more common.
• With follicular thyroid cancer, lung, bone, brain, liver, bladder, and skin are potential sites of
distant spread. Lymph node involvement is far less common than in papillary carcinoma.ts

19. FOLLICULAR THYROID CANCER
• CHARACTERISTICS OF FOLLICULAR THYROID CANCER
• Peak onset of follicular thyroid cancer is between ages 40 and 60 years old.
• Follicular thyroid cancer is more common in females than males by 3:1 ratio.
• The prognosis directly related to tumor size (less than 1.0 cm [3/8 inch] is a good prognosis).
• This cancer is rarely associated with radiation exposure.
• Cancer that spreads to lymph nodes is uncommon (~10%) in follicular thyroid cancer.
• Invasion into vascular structures (veins and arteries) within the thyroid gland is common.
• Distant spread (to lungs or bones) is uncommon, but it is more common than with papillary cancer.
• Overall cure rate is high (near 95% for small lesions in young patients), but this decreases with age.

20. TYPES OF FOLLICULAR THYROID CARCINOMA

21. GROSS AND MICROSCOPIC FEATURES (MINIMALLY
INVASIVE FOLLICULAR CARCINOMA)

22. WIDELY INVASIVE FOLLICULAR CARCINOMA (GROSS
SPECIMEN)

23. FOLLICULAR PATTERNED TUMOURS OF UNCERTAIN
MALIGNANT POTENTIAL
The most controversial development relating to thyroid pathology over the past
two decades has been the recognition and incorporation into mainstream
classification of a group of well-differentiated follicular-patterned neoplasms
(intermediate or borderline) that lie morphologically and behaviourally between
follicular adenoma and follicular carcinoma/FVPTC – tumours of uncertain
malignant potential (atypical adenoma, adenoma with atypia, well-Differentiated
tumour of uncertain behaviour).

24. NON-INVASIVE FOLLICULAR THYROID NEOPLASM
WITH PAPILLARY-LIKE NUCLEAR FEATURES.

25. HOW TO REACH A DIAGNOSIS?
• PTC- Papillary thyroid cancer
• WDC-NOS- well-differentiated
carcinoma, not otherwise
specified.
• WDT-UMP- well-differentiated
tumour of uncertain malignant
potential.
• MIFC- minimally invasive follicular
carcinoma.
• WIFC- widely invasive follicular
carcinoma.

26. HOW TO DIAGNOSE CLINICALLY? (THE THYROID
NODULE)
• CLINICAL ASSESSMENT
• HISTORY
The majority of patients with thyroid tumours will present with a
solitary thyroid nodule. The patient’s age is very important in
determining the likelihood of a solitary nodule being malignant. A truly
solitary thyroid nodule in a patient under 20 years old has a 25 percent
chance of malignancy. The risk lessens in middle age to around 7-10
percent and increases again after the age of 50. Solitary nodules that
occur at either extreme of life are more likely to be malignant. Around 10
percent of patients with DTC will present with palpable neck node
metastasis and 3-5 percent will have hoarseness or obstructive symptoms.
The other important historical risk factors in the development of thyroid
cancer are radiation exposure, particularly in childhood, and a family
history of thyroid disease.

27. FACTORS INCREASING LIKELIHOOD OF MALIGNANCY
IN A THYROID NODULE.
• A nodule is more likely to be malignant if:
• History of neck irradiation in childhood.
• Endemic goitre
• Hashimoto’s thyroiditis (risk of lymphoma)
• Prolonged stimulation by elevated TSH
• Solitary thyroid nodule
• Family or personal history of thyroid adenoma
• There is a history of previous thyroid cancer
• Genetic Factors
1. Familial thyroid cancer
2. Cowden syndrome
3. Familial adenomatous polyposis

28. FACTORS INCREASING LIKELIHOOD OF MALIGNANCY
IN A THYROID NODULE
• There is an enlarging nodule (particularly on suppressive doses of thyroxine)
• The nodule develops in a person under 14 or over 65 years of age
• The patient is male

29. EXAMINATION
• Distinguishing accurately between benign and malignant thyroid nodules can be difficult
although certain clinical features of a thyroid nodule are typical of DTC.
• Papillary cancers tend to be harder than follicular tumours and have a higher rate of nodal
metastasis.
• A degree of fixation to surrounding structures may be associated with extra thyroid
extension.
• The neck must be palpated carefully for lymph nodes; levels of involvement are 6,3,2,4,5 and
1 in decreasing order of frequency.
• Finally the pharynx, larynx and upper trachea should be examined by direct fiberoptic
endoscopy to look for vocal cord paralysis or invasion by tumor.

30. INVESTIGATIONS - CYTOLOGY
• The interpretation of FNAC by an experienced
cytopathologist has had a major impact in the
management of nodular thyroid disease.
• FNAC is a safe, cheap and reliable investigation,
and along with FT4, TSH, serum Ca and thyroid
antibody levels together with a USG should
encompass the primary investigations in the
management of thyroid nodules.
• The classification of thyroid cytopathology is
shown in the table.

31. CYTOLOGY
• A Thy5 result can only be possible in papillary and medullary thyroid cancer where a
constellation of the expected cytological features are present.
• In follicular variant papillary tumours, there is significantly more difficulty in interpreting
the cytological findings because many features overlap with those of hyperplastic nodules
or follicular neoplasms. The aspirate from such a lesion is likely to be classified as Thy4.
• The Thy3 category essentially represents lesions that have features that pathologists can
only call a ‘Follicular neoplasm’. This reflects the fact that the diagnosis of Follicular
carcinoma is made only by observing capsular or vascular invasion and this cannot be
determined by FNAC.
• The cytological features of a follicular neoplasm demonstrate a cellular aspirate with scant
colloid.

32. • Cytology representing a benign pattern (Thy2)
would contain more colloid and a sparse cellular
population with no repetitive microfollicular
pattern and no atypical cellular features.
• Non diagnostic cytology (Thy1) has been shown
to be malignant in up to 9 Percent of cases on
permanent histological examination. The
recommendation is to initially repeat the FNAC in
this situation.

35. LABORATORY INVESTIGATIONS
• Investigation of a thyroid nodule should include TSH, T3, T4 and thyroid antibodies.
• An elevated TSH is associated with an increased risk of malignancy.
• Antibodies are useful in the interpretation of the thyroid function tests, the prediction of
postoperative subclinical hypothyroidism and in the assessment of the serum thyroglobulin.
• Preoperative measurement of thyroglobulin is not usually helpful unless the patient has had
previous treatment.
• Serum calcium levels can also be considered to exclude hyperparathyroidism and to provide a
baseline pre-surgery.

36. RADIOLOGY- ULTRASOUND
• Ultrasound is useful in measuring tumour size, diagnosing multinodular goitre and excluding contralateral
disease.
• Ultrasonography can also be used to evaluate complex cysts and can distinguish purely cystic nodules.
• Calcification may be detected and although it occurs in both benign and malignant disease, it tends to have
different features.
• Colour Flow Doppler Sonography (CFDS), in addition to conventional USG has been recently used to identify
different types of blood flow within solid thyroid nodules, with type 3 (marked intranodular) flow being a
statistically significant criterion to suggest malignant disease.
• Usg is also useful for assessment of Central and lateral neck lymph nodes and to detect metastasis which can
be difficult to assess clinically. Features suggesting malignancy in lymph nodes include increased size, rounded
and bulging shape and loss of hilar echoes.
• There are limitations to the ability of USG to detect malignancy and biopsy has been suggested to be a
superior modality.

37. ULTRASOUND
CLASSIFICATION OF
THYROID NODULES

38. SCINTIGRAPHY
• Scintigraphy was previously routinely used for investigation of the solitary thyroid nodule. Iodine-123 is
probably the optimal radionuclide for thyroid imaging because of its physiological properties but, as it is
cyclotron generated, cost and availability limit its use.
• The radionuclide technetium 99, in the chemical form of pertechnetate is trapped (but not organified) by the
thyroid gland in a similar manner to the iodide ion. It has a 6-hour half-life and is cheap and readily available
with a low radiation dose; it is therefore now used in thyroid imaging.
• Pertechnetate uptake, however, is low (0.4-4 per cent) and does not always match the physiological uptake of
iodide which leads to a high background activity. Nonetheless, with careful attention to scanning technique
the majority of nodules greater than 5 mm diameter can be visualized on scintigraphy.
• False negative results are often associated with smaller lesions in the isthmus, but these are usually easy to
palpate and therefore do not cause a significant problem.
• More than 90 per cent of lesions identified will not concentrate the radio nuclide (‘cold’ nodules). These
clinically solitary non-func tional nodules may be an adenoma, a carcinoma or a cystic or dominant nodule in a
non-palpable multinodular goitre.
• Truly functioning nodules (also called ‘hot’ or ‘toxic’ nodules) are highly unlikely to be malignant so this investi
gation is probably not cost-effective for cancer assessment. Scintigraphy is now only used to identify hot
nodules in a patient with elevated thyroxine or suppressed TSH levels.

39. APPEARANCE (HOT AND COLD NODULES)

40. CT AND MRI
• CT of the neck and thorax is of help in assessing the extent and relationship of larger thyroid
tumours, particularly those involving the larynx, trachea, pharynx, oesophagus and major
vessels. It is also used to demonstrate nodal deposits in the neck and mediastinum, direct
retro sternal extension and pulmonary metastases.
• MRI allows multiplanar imaging of the neck and has good inherent soft tissue contrast. Vessel
involvement can be assessed with MR angiography. Additional advantages over CT include
the fact that iodine containing contrast is not required and there is no radiation exposure.
Both MRI and CT may be difficult investigations for patients with a com promised airway for
whom lying flat is uncomfortable.

41. INVESTIGATING A SOLITARY/DOMINANT THYROID
NODULE- PROTOCOL

42. ASSESSING THYROID
ENLARGEMENT

43. PROGNOSTIC FACTORS
• Patients under 45 years have a better prognosis and women in general do better than men.
• Tumours that present a advanced age generally have a poorer prognosis.
• There is a linear relationship between the size of the tumour and prognosis and the grade of
tumour is also important.
• The tall cell variant of PTC is particularly aggressive as are those follicular tumours which
exhibit extensive vascular invasion.
• Patients with PTC fare better than those with follicular tumours. The presence of either local
invasion or distant spread is associated with a worse prognosis, as are nodal metastases,
particularly in elderly patients.

44. PROGNOSTIC SCORING SYSTEM

45. STAGING
• The staging system that is most widely used for DTC is the TNM classification for malignant
tumours. This classification is based on some of the prognostic factors listed before. There
should be histological confirmation of the disease and division of cases by histological type.

46. MOLECULAR GENETICS
• Malignant thyroid tumours generally have a monoclonal origin, suggesting that genetic events in a
single cell account for their development.
• Several oncogenes are known to play an important role in thyroid carcinogenesis and
development.
1. RET/PTC – RET is a proto oncogene present on chromosome 10q. RET rearrangements are found
frequently in tumours from paediatric patients and those exposed to radiation in childhood.
They are more frequent in papillary microcarcinomas, classic papillary and diffuse sclerosing
variant and rare in Follicular variant.
2. RAS – RAS mutations are uncommon in conventional papillary thyroid cancer (<10 percent) but
are frequently present in follicular variant PTC. RAS mutations are equally prevalent in Follicular
adenomas and carcinomas. These mutations predispose to development of poorly or
undifferentiated carcinomas, such as anaplastic tumours.
3. TRK – TRK is an oncogene located on chromosome 1q22, which codes for transmembrane
tyrosine kinase receptor. It is mutated in 10-25 % papillary carcinomas.
4. BRAF – The RAF proteins are serine/threonine protein kinases that are critically involved in cell
proliferation, differentiation and apoptosis. BRAF type is prominent form in thyroid follicular
cells. BRAF mutations have been demonstrated in 40-70 percent of PTC of most types, except
follicular variant PTC. There is evidence that BRAF mutations are with poor clinical Outcome.

47. MOLECULAR GENETICS CONTD.
5 – PPPAX8-PPAR – This type of rearrangement in seen more commonly in Follicular carcinomas
compared to adenomas and are more frequent in patients with a history of radiation exposure.
PAX8-PPAR gamma positive follicular carcinomas are likely to be widely invasive while tumours
negative for this rearrangement are minimally invasive.

48. ONCOGENES IMPLICATED IN THYROID CANCERS

49. TREATMENT OF DTC (SURGICAL)
• SURGERY IS THE MAINSTAY OF TREATMENT OF DTC. AIMS OF THERAPY ARE:
1. To remove the primary tumor disease that has spread beyond the thyroid capsule and the
involved lymph nodes.
2. To minimize disease related morbidity.
3. To permit accurate staging of the disease.
• Thyroidectomy facilitates post operative treatment with radioactive iodine and appropriate
treatment minimizes the risk of disease recurrence and metastatic spread.

50. SURGICAL OPTIONS FOR TREATMENT
• Surgical options for treatment of the thyroid gland should be limited to:
1. LOBECTOMY – The complete removal of one thyroid lobe including the isthmus.
2. NEAR TOTAL LOBECTOMY – A total lobectomy leaving behind the smallest amount of
thyroid tissue (less than 1 gm) to protect the recurrent laryngeal nerve.
3. NEAR TOTAL THYROIDECTOMY – Either a complete lobectomy on one side and near total on
other or a bilateral near total lobectomy.
4. TOTAL THYROIDECTOMY – Complete removal of both lobes of the gland, the isthmus and
the pyramidal lobe.

51. TYPES OF THYROIDECTOMY

52. SURGICAL OPTIONS FOR SOLITARY THYROID NODULE

53. SURGICAL MANAGEMENT OF THE THYROID GLAND IN
PAPILLARY THYROID CANCER
• Patients with cancers 1 cm in diameter or less without evidence of lymph node metastases
can be adequately treated by lobectomy and thyroxine suppressive therapy.
• In the majority of patients with tumours greater than 1 cm, multifocal disease, familial
disease, extrathyroid extension and positive lymph node involvement or distant metastases,
total thyroidectomy is indicated.
• Total or near-total thyroidectomy is also indicated in those with a history of previous radiatio
exposure in childhood.
• If the diagnosis of PTC is made after lobectomy and completion thyroidectomy is required,
the operation should be offered within 8 weeks of histological diagnosis. In this situation, if
the risk of recurrence is judged to be low, lobectomy alone may be appropriate in tumours
larger than 1 cm in diameter.

54. SURGICAL MANAGEMENT OF THE THYROID IN FTC
• FNAC cannot differentiate between hyperplasia, a benign colloid nodule, a follicular adenoma or
carcinoma and Thy3 cytology mandates at least a lobectomy and subsequent histological
examination.
• Frozen section is not helpful when FNAC demonstrates a follicular lesion and should not be used in
lobectomy for Thy3 lesions.
• A follicular carcinoma less than 1 cm in diameter with no capsular invasion should be treated by
lobectomy only. Patients with follicular carcinoma showing evidence of vascular invasion should
undergo total thyroidectomy.
• Low risk patients (females, age less than 45 years) with tumours less than 2 cm in diameter may be
managed by lobectomy and thyroxine therapy following multidisciplinary team (MDT) discussion
and informed consent.

55. SURGICAL MANAGEMENT OF THE NECK IN DTC
• In PTC, nodal disease in level VI discovered at surgery is treated with a central (level VI) neck
dissection.
• If suspicious or clinically involved nodes are identified in the lateral neck and are confirmed
by FNAC or by intraoperative frozen section, then a selective neck dissection incorporating
levels IIa–Vb with preservation of the spinal accessory nerve (SAN), Internal jugular vein (IJV)
and sternocleidomastoid muscle (SCM) should be performed.
• The guidelines also state that node-positive FTC should be managed in a similar way. IN
patients with PTC and clinically uninvolved nodes but who are deemed high-risk (i.e. any of
the following features: male, age greater than 45 years, tumours greater than 4 cm diameter,
presence of extracapsular or extrathyroidal disease), then total thyroidectomy and level VI
node dissection should be performed.

56. SURGICAL MANAGEMENT OF THE NECK IN DTC
CONTD.
• If the neck disease involves surrounding structures such as the IJV, SCM or skin, then these
structures, should also be excised as part of the lateral neck dissection. Level IIb may also be
addressed as there is evidence of moderate risk of these nodes being involved and recurrent
disease is difficult to treat at this site.

57. MANAGEMENT OF EXTRA THYROID EXTENSION
• Although DTC is usually an indolent disease with a good prognosis, 8–26 per cent of patients
can present with locally advanced cancer with invasion of surrounding structures,leading to
increased morbidity and mortality.
• The presence of extrathyroidal extension (ETE) is associated with higher rates of overall
recurrence and mortality than tumours confined to the thyroid, with local airway invasion being
the cause of death in up to 50 per cent of deaths due to DTC.
• Although ETE occurs in both papillary and follicular carcinomas with equal frequency, it is seen
more frequently in PTC due to its higher incidence. The prognostic risk factors significantly
associated with ETE in PTC include age greater than 50 years, tumour size greater than 4 cm,
non- encapsulated tumours and aggressive histological variants.
• The strap muscles, recurrent nerve and trachea are the most common extrathyroid structures
involved in the central neck compartment; the oesophagus is less so but is usually associated
with laryngotracheal invasion.

58. CONTD.
• In the lateral neck the SCM, IJV, carotid artery, cranial nerves X, XI, phrenic and cervical sympathetic
chain can all be involved either from direct thyroid tumour extension or from extranodal extension from
cervical metastatic nodes.
• ETE is associated with higher rates of lymph node metastases and distant metastases than tumours
without ETE and it is also seen more commonly in patients who present with recurrent DTC.
• The UK guidelines recommend incomplete excision of tumour, preservation of one or both recurrent
laryngeal nerves and treatment with postoperative radioactive iodine and thyroxine suppression, plus
or minus external beam radiation if both recurrent laryngeal nerves are threatened.
• If there is gross invasion of the trachea or larynx, and particularly if there is intraluminal involvement,
then radical resection including circumferential or partial resection of the tracheal wall and partial or
total laryngectomy will reduce local recurrence rates and improve survival.
• An alternative to surgery is external beam radiotherapy plus or minus radioactive iodine. In patients
where there is ETE, it has been shown that the addition of external beam radiation therapy offers
improved locoregional control even where gross macroscopic disease has been completely excised.

59. SURGICAL TECHNIQUE IN DTC (THYROIDECTOMY)
When a tumour is confined to the thyroid gland without any extrathyroidal
extension, or when there is simply a suspicion that a nodule may be
malignant, surgery is performed in a similar manner as for benign disease.
• A skin incision is made in, or closely paralleling, a low anterior neck skin
crease (Kocher’s incision) Flaps are raised in a sub-platysmal plane, or in
a plane deep to the anterior jugular veins if the surgeon prefers to ligate
these.
• The flaps are then sutured back, or kept open with a self-retaining Joll’s
retractor. Strap muscles are either separated in the midline, elevated
and retracted laterally or they are divided and retracted depending on
the surgeon’s preference.
• The thyroid gland is then exposed, the paracarotid tunnel entered and
the middle thyroid vein divided. Dissection usually begins at the
superior thyroid pole.

60. THYROIDECTOMY CONTD.
• The superior thyroid vessels are individually ligated and divided, and the superior pole is
incrementally mobilized.
• As the mobilization proceeds, Joll’s triangle is explored and the external branch of the
superior laryngeal nerve may be seen at this point and identified and preserved.
• The posterior branches of the superior thyroid artery are often not dissected at this point
because of their importance in the blood supply to the superior para-thyroid glands. At this
point, a superior parathyroid gland may be found medial to the upper pole in Joll’s triangle
although in 80 per cent of cases it is in its usual position, posterosuperiorly situated above
the inferior thyroid artery.

61. CONTD.
• Once the muscle and fascia have been elevated away from the inferior
pole, the inferior thyroid veins are individually ligated and divided and
the anterior surface of the trachea exposed.
• The gland is mobilized medially, both parathyroids identified together
with the recurrent laryngeal nerve. The lower parathyroid is usually
found below and medial to the inferior thyroid artery close to or
actually within the thyrothymic ligament.
• The recurrent laryngeal nerve is identified (with minimal disturbance)
in the thyroid bed where it makes up the third side of Beahr’s triangle
the other two sides being the inferior thyroid artery and the common
carotid artery.

62. CONTD.
• An extracapsular dissection technique is then used on the gland across a broad front
preserving the recurrent laryngeal nerve and two parathyroid glands. The assistant applies
gentle but firm gradual sequential upward and medial traction using a swab (a technique
known as ‘creeping’), taking care to keep out of the surgeon’s line of vision, to elevate the
lobe from the thyroid bed as the capsule is being exposed.
• Vessels are ligated directly on the surface of the thyroid gland capsule and as dissection
proceeds medially the parathyroids are noted to peel away within the fascia maintaining their
blood supply. As the capsular dissection continues medially and the ligament of Berry is
approached, the recurrent laryngeal nerve is seen and preserved within the fascia.
• At the ligament of Berry, once the nerve is clear of the thyroid gland, sharp dissection on the
trachea allows reflection of the lobe off the trachea to the point where the isthmus joins the
contralateral lobe.

63. CONTD.
• A Roberts clamp is placed across the gland and
the lobe and isthmus excised if a lobectomy is
being performed; a similar dissection is
performed on the contralateral lobe for a total
thyroidectomy.
• The parathyroids are carefully inspected and if
one is particularly congested or devascularized
it should be resected, morselized and placed
into pockets in either the sternomastoid muscle
or the brachioradialis muscle in the forearm.
• Haemostasis is established using a Valsalva
manoeuvre and particular attention paid to the
‘triangle of concern’, which is where small blood
vessels have been ligated medial to the
recurrent laryngeal nerve. The triangle consists
of the recurrent laryngeal nerve, the trachea
and the root of the neck.

64. SURGICAL OPTIONS FOR LYMPH NODE INVOLVEMENT
Surgical management of involved cervical lymph nodes requires an understanding of the lymph
node anatomy of the neck and likely patterns of spread of disease to the lymph nodes. The neck
is divided into lateral and central compartments. Each compartment is further divided into
levels as outlined.

65. CENTRAL NECK DISSECTION (LEVEL VI & VII)
• Although nodes can occur in a variety of locations
within the central neck, the majority of central neck
lymph nodes occur in four discrete regions. As shown
in the figure. (Regions A to D)
• Central neck dissection may be of benefit in tumours
>4 cm in size and in tumours with extrathyroidal
extension, but the evidence is unclear.
• Prophylactic central neck dissection is not
recommended in patients who have low-risk disease,
or have tumours <4 cm in size with classical PTC and
no extra-thyroidal extension.

66. STEPS OF CND
1. Initially, the RLN is skeletonized from the cricothyroid joint to the level of the sternal notch
with the overlying tissue laid lateral and medial. Once the nerve can be seen along its length,
it is carefully elevated off the underlying tissues. Vessel loops can be used but care should be
taken not to apply any traction to the nerve.
2. The node bearing tissue is then dissected as a compartment from lateral at the IJV passing it
deep to the nerve and finally resecting it off the trachea.
3. At the lower end, the thymic remnants and associated fatty tissue and lymph nodes are
dissected and removed via the neck and the trachea is then completely skeletonized.
4. The key to preserving parathyroid function is to retain the vascular supply to the superior
parathyroids while resecting and reimplanting the inferior ones.

67. CND
• CND Is associated with increased morbidity,
including higher rates of recurrent laryngeal nerve
damage and temporary and permanent
hypoparathyroidism.
• One technique that reduces this risk is to divide
level VI into two parts, VIa and VIb, separated by the
recurrent laryngeal nerve.
• For small cancers in low risk patients, dissection
could be confined to level VIa, greatly reducing the
risks to the RLN and parathyroid glands. For high risk
patients and those with large tumours, a full level VI
dissection may be undertaken.

68. GUIDELINES FOR DIFFICULT CASES
1. Make an adequate incision
2. Do the easy side first
3. Always consider cancer
4. Consider total thyroidectomy for many benign and malignant cases; high-risk
patients may need a level VI neck dissection
5. Try to identify the recurrent laryngeal nerve and parathyroid glands
6. Know the location of the external branch of the superior laryngeal nerve
7. Consider using a nerve monitor
8. Achieve good access in retrosternal goitre, do the easy side and the upper pole
first, and divide the strap muscles at least on one side
9. Do not hesitate to split the chest or sacrifice on recurrent laryngeal nerve if
malignancy is present

69. OUTCOME MEASUREMENTS FOLLOWING TREATMENT
• Adequate primary surgery
• Incidence of vocal cord paralysis
• Incidence of hypoparathyroidism (temporary and permanent)
• Achievement of TSH suppression
• Provision and treatment with radioiodine postoperatively when indicated
• Regular monitoring of serum thyroglobulin Abnormal thyroglobulin acted upon
• Disease-free interval
• Quality of life
• Survival

71. MANAGEMENT OF RECURRENT DISEASE
• There are a number of factors that predict for higher rates of recurrence. These can be split
into patient (age greater than 60 or less than 20), tumour (size greater than 4 cm,
multifocality, postoperative residual disease and lymph node involvement) and treatment
(less than near-total thyroidectomy and the lack of use of radioiodine).
• Surgery is again the mainstay of management of local and regional recurrence, particularly
with palpable disease, however there is evidence that disease detected by scintigraphy can
be adequately treated using ablative doses of I. 131
• A comprehensive compartment orientated clearance of level VI should be performed with
skeletonization of the recurrent laryngeal nerves and careful preservation of the parathyroids
on vascular pedicles.
• Recurrent nodal disease in the lateral neck is more frequent in the very young and in those
who have had positive nodes previously treated, particularly those with large numbers of
involved nodes.

72. • If the recurrence is not in the thyroid bed or cervical lymph
nodes, then it is likely to involve one or more of the sites
listed in Box.
• Metastatic disease involving lung and other soft tissue
areas are not usually amenable to surgery and should be
treated with 131I therapy.
• Extensive bony metastases are generally not curable by
131I therapy alone. For solitary or limited number of bony
metastases that are not cured by 131I therapy, external
beam radiotherapy, with or without resection and/or
embolization should be considered in selected cases.

73. RADIOIODINE ABLATION
• For radioiodine ablation to be effective, a total thyroidectomy is required, and therefore
patients who have had a hemithyroidectomy require a completion thyroidectomy prior to
consideration of this treatment.
• The benefits of radioiodine ablation have to be weighed carefully against the potential side
effects. Positive effects include the possibility of improved survival, reduced recurrence and
better monitoring with thyroglobulin in the long term.
• Patients in whom radioiodine is indicated include those patients with tumours >4cm or with
gross extrathyroidal spread or distant metastasis. These patients will receive an ablative dose
of radioiodine followed by a treatment dose.
• Patients for whom radioiodine is not indicated include those who have unifocal or multifocal
tumours <1cm in size which are histologically classed as papillary or follicular variant, or
minimally invasive follicular cancer, with no angioinvasion or extension outside the thyroid
capsule.

74. • High treatment doses of radioiodine are recommended in patients who have gross residual
disease or distant metastases. These patients may require repeat treatments every 6–
12 months, especially those with disease not amenable to surgery.

75. EXTERNAL BEAM RADIOTHERAPY
• Patients with gross evidence of local tumour invasion at surgery are candidates for external
beam radiotherapy (EBRT), as are those with residual or recurrent tumour that is non-
radioiodine avid. Intensity-modulated radiotherapy (IMRT) is the method of choice as it
reduces damage to other surrounding tissues19 and reduces toxicity.

76. FOLLOW UP

77. MINIMALLY INVASIVE AND ROBOTIC THYROID
SURGERY
Endoscopic thyroidectomy techniques
1. Endoscopic anterior breast approach
2. Endoscopic axillary approach
3. Endoscopic axillo breast approach
4. Endoscopic post auricular and axillary
approach
5. Endoscopic transoral approach
Robotic thyroidectomy procedures
1. Robotic transaxillary
2. Robotic retroauricular
3. Robotic transoral

78. MINIMALLY INVASIVE THYROIDECTOMY
• Technological developments of the endoscope and energy sealing devices provided essential
prerequisites to develop small incision thyroidectomy techniques. These are known by
several euphemisms:
1. minimally invasive video-assisted thyroidectomy (MIVAT) or Miccoli technique
2. minimally Invasive thyroidectomy (MIT)
3. Endoscopic-assisted thyroidectomy (EAT) and finally
4. The Henry technique.
Endoscopic-assisted thyroidectomy more accurately describes these techniques in practice.

79. INSTRUMENTS IN MIVAT

80. THANKYOU