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414
Manipal Manual of Surgery
functional. About 5–10% of these tumours are
bilateral and thyrotoxicosis may occur in 8 to 10% of
patients. Patients present with variable degree of
thyrotoxicosis and have lower abdominal pain or
mass. Treatment—patient to be rendered euthyroid
followed by removal of involved ovary. Therapeutic
radioiodine may be required for metastatic disease.
7. Trophoblastic thyrotoxicosis: HCG secreted by vesi-
cular mole, choriocarcinoma or metastatic embryonal
carcinoma act like TsAb causing thyrotoxicosis.
8. Hamburger thyrotoxicosis: It is an unusual and rare
form of epidemic exogenic thyrotoxicosis. One such
incidence was reported in United States in 1984–85
due to inclusion of large quantities of bovine thyroid
in beef preparations.
NEOPLASTIC GOITRE
Adenoma
• The benign tumours of the thyroid gland are not
uncommon. They present as a solitary nodule, thus
causing a worry to the clinician. Adenomas are of
follicular type.
• The diagnosis is established by histological examina-
tion.
• Adenomas are treated by hemithyroidectomy/
lobectomy.
• However, FNAC cannot distinguish between a
follicular adenoma and follicular carcinoma. Hence,
a frozen section can be done.
SU22.4: Describe the clinical features, classification and
principles of management of thyroid cancer.
MALIGNANT TUMOURS
1
• Thyroid is the only endocrine gland wherein malignant
tumours are easily accessible to clinical examination.
• Thyroid is the only endocrine gland wherein malig-
nant tumours occur in children, young age, middle
age, old age, and in both sexes.
• Thyroid is the only endocrine gland wherein malig-
nant tumours spread by all possible routes—local,
lymphatic and blood spread.
• Thyroid is the only endocrine gland wherein malig-
nant tumours are usually nonfunctional. Malignant
tumours of the thyroid are common. They are
interesting tumours, having good prognosis, if
diagnosed early. Papillary and follicular carcinomas
are well differentiated, medullary carcinoma is poorly
differentiated.
PAPILLARY CARCINOMA THYROID (PCT)
Thyroid Oncogenesis
• Mutations in oncogenesis will result in malignancies.
• In case of thyroid, rearrangement of RET (rearranged
during transfection) and NTRKI tyrosine kinase
result in sporadic papillary carcinoma (neurotrophic
receptor, tyrosine kinase receptor)
• Specially in papillary carcinoma thyroid RET proto-
oncogene is predominantly found in malignant tissue.
• RAS, kinase and 13 type (BRAF) are result of down-
stream pathway of RET and NTRKI mutations. BRAF
mutations can result in poorly differentiated cancer.
• 40% of thyroid tumour including follicular adenoma
will have RAS gene point mutations.
• K-RAS mutations more often found in radiation
induced-papillary thyroid carcinomas
• Radiation damages p53 tumour suppressive gene.
p53 gene plays an important role in cell cycle
progression. p53 gene has been found in anaplastic
thyroid cancer.
Radiation and Thyroid Cancer
• Neoplastic nodules are much more common when
thyroid gland is exposed to long-term ionising
radiation.
• High amount of radiation causes increased incidence
of thyroid cancers.
• Risk of cancers in adults is high when they had
contacted low or moderate doses of irradiation
during childhood as found in survivors of Hiroshima
and Nagasaki.
• Generally after 5 years of radiation exposure
(radiation to head and neck for childhood lymphoma
or too many CT scans for head and neck malignancy),
papillary carcinoma thyroid can occur.
Aetiology
• Irradiation to the neck during childhood: In olden
days, radiotherapy was given for benign conditions
such as acne in teenagers or enlarged tonsils or thymus
gland. Those children had increased risk of papillary
carcinoma thyroid. These indications are obsolete
now. However, accidental radiation to the neck or
radiation given to Hodgkin’s lymphoma can precipitate the development of papillary carcinoma thyroid.
1
These were the teachings or sayings of Late Prof Sharath Chandra, FRCS, Department of Surgery, Madras Medical College, Chennai (conveyed to me by
Section II • General Surgery
Late Prof Subbu, MMC, Chennai, when for the first and last time, I sat with Prof Subbu as a co-examiner at Govt. Medical College, Coimbatore, 1998).
Thyroid Gland
415
• It can be a complication of Hashimoto’s thyroiditis.
• Papillary cancer of thyroid occurs more often in
patients with Cowden’s syndrome, Gardner’s
syndrome or Carney’s syndrome.
• Associated mutations: Chromosomal translocation
involving RET proto-oncogene (tyrosine kinase)
chromosome 10q11.
Pathology
• It is made up of colloid-filled follicles with papillary
projections. In some cases, concentric, lamellated
calcific structures are found which are called
psammoma bodies. (Psammoma bodies are also
found in meningioma, and papillary serous
cystadenoma of the ovary.) These are suggestive of
papillary carcinoma of thyroid. Nuclear grooving
intranuclear cytoplasmic inclusion (INCI)
and
are diagnostic of papillary carcinoma thyroid.
Characteristic pale, empty, nuclei are present in a few
cases which are described as Orphan Annie-eye
nuclei. Thyroid gland has very rich intrathyroidal
lymphatic plexus. Papillary carcinoma can be unifocal
or multifocal (Figs 37.22 and 37.23).
• Papillary microcarcinoma: They measure 1 cm or less
in diameter. Distant metastasis is extremely rare.
Hence, a simple hemithyroidectomy is the treatment
of choice.
Fig. 37.22: Orphan Annie-eyed nuclei
Fig. 37.23: PCT showing papillae with fibrovascular cores lined
by follicular cells with Orphan Annie nucleus (Courtesy: Dr Laxmi
Rao, Head, Department of Pathology, KMC, Manipal)
• Follicular variant of papillary cancer: This is a mixed
lesion with a predominance of follicles over papillae.
These are treated by total thyroidectomy. It is called
Lindsay tumour.
• Tall cell papillary cancer: This is an aggressive and
rapidly growing tumour. It occurs in elderly patients
and should be treated by total thyroidectomy.
• Other details are given in Key Box 37.20.
Key Box 37.20
Pathology of Papillary Carcinoma Microscopy
Calcification
Cystic changes/necrosis
Cuboidal pale cell with grooving
Crowded nuclei
Cytoplasmic inclusions—intranuclear
Cartoon character—Orphan Annie
Calcified laminated, basophilic, spherical concretions—
Psammoma bodies
Observe 7 Cs
Types—Woolner classification
Minimal/occult/microcarcinoma: Tumour of 1 cm or
less in size with no invasion/no lymph node metastasis
Intrathyroidal: Confined to thyroid gland
Extrathyroidal: Invasion of adjacent structures.
Clinical Presentation
• As solitary nodule: Young females are commonly
affected (in the age of 20–40 years). It can present as
a solitary nodule (Fig. 37.24) Nodule can be firm or
hard. Unlike a nodule of anaplastic malignancy,
nodule of papillary carcinoma is usually mobile in
vast majority of cases. However, when it occurs in
elderly patients, it can be rapidly growing. Ulceration
and fungation is rare but can occur only in neglected
cases as in Fig. 37.25.
• As enlarged lymph node:
Very often, the lymph
nodes in the lower deep cervical region—level 3 and
level 4 are involved and they can be huge size also as
in Figs 37.26 and 37.27.
• As occult primary with palpable nodes: In these
cases thyroid gland may or may not be palpable.
When thyroid gland is not palpable, it is called occult
(hidden). However, papillary carcinoma less than
1.5 cm in diameter is also called ‘occult’.
• Interestingly a few patients present as lateral aberrant
thyroid
or even a cystic swelling which is misdiag-
nosed as even a lymphatic cyst (Key Box 37.21).
• Tracheal fixity, common carotid artery engulfment
and recurrent laryngeal nerve infiltration are very uncommon features of papillary carcinoma thyroid. But
can occur in advanced cases more so in elderly patients.
Section II • General Surgery
416
Fig. 37.24: Papillary carcinoma thyroid presenting as solitary
nodule. FNAC gave the correct diagnosis. Total thyroidectomy
was done in this patient
Manipal Manual of Surgery
Key Box 37.21
Papillary Carcinoma—Lymph Node
Metastasis—Peculiarities
1. They may be palpable even when thyroid gland is not
palpable—occult primary
2. Very slow growing
3. Very often, they are intracapsular
4. They need not be hard, are often cystic and firm in
consistency
5. At operation, they are bluish in colour because of
rupture of the papillae
6. Presence of lymph node metastasis does not affect the
prognosis
7. Mostly central neck nodes and jugular chain of lymph
nodes are cleared. Dissection of posterior triangle and
suprahyoid dissection is not necessary.
Prognostic Criteria
There are many prognostic criteria that have been used
in cases of well-differentiated carcinoma. Various
scoring systems are available for well-differentiated
carcinomas. Some examples are given below.
Fig. 37.25: Papillary carcinoma thyroid in a 75-year-old lady—
it behaves aggressively in elderly patients. Total thyroidectomy
was done (uncommon presentation)
Fig. 37.26: Another case of papillary carcinoma thyroid with
huge lymph node secondaries—advanced, neglected case
Fig. 37.27: Same patient as in Fig. 37.26—underwent total
thyroidectomy with functional block dissection of the neck. See
Section II • General Surgery
also exposed common carotid artery
AMES scoring
A: Age less than 40 years—better prognosis
M: Distant metastasis—poor prognosis
E: Extent of tumour extracapsular spread—poor prognosis
S: Size less than 4 cm, good prognosis
AGES scoring
A: Age less than 40 years—better prognosis
G: Grade of the tumour—high grade—poor prognosis
E: Extracapsular spread—poor prognosis
S: Size less than 4 cm—good prognosis
MACIS scoring
M: Metastasis
A: Age
C: Completeness of resection
I: Invasion
S: Size
Histological Surprise
If a patient undergoes hemithyroidectomy for
suspicious adenoma and histopathology reported is
papillary carcinoma, dilemma exists as to how to
proceed. Straightaway, one can advise the patient for
completion (total) thyroidectomy. According to another
school of thought, if the patient is in low-risk category
with intrathyroidal malignancy and other factors
favoring good prognosis, then ‘wait and watch’ policy
can be undertaken.
Thyroid Gland
417
Investigations
• Ultrasound imaging and image guided FNAC: It
is the first investigation of choice. As in breast
imaging (BIRADS) in thyroid diseases also various
findings have been classified depending upon
composition, echogenecity, shape, margin and
echogenic focus. Imaging by ultrasound has been
described as TIRADS (Fig. 37.28). Hypoechoic lesion
with solid components, taller than wide, richly
vascular/microcalcification and with or without
jugular lymphadenopathy are suggestive of malignancy. In all such cases, ultrasound guided FNAC is
done. Intranuclear inclusion bodies and nuclear
grooving confirm diagnosis of papillary carcinoma
thyroid.
• Image-guided FNAC:
STAGING AJCC, 8th edition, 2018, TNM definitions
Primary tumour (pT) for papillary, follicular, poorly
differentiated, Hürthle cell and anaplastic thyroid
carcinomas:
• TX: Primary tumour cannot be assessed
• T0: No evidence of primary tumour
Tumour <2 cm in greatest dimension limited to the thyroid
• T1:
• T2: Tumour >2 cm but <4 cm in greatest dimension limited to
the thyroid
Tumour >4 cm limited to the thyroid or gross extrathyroidal
• T3:
extension invading only strap muscles
– T3a:
– T3b: Gross extrathyroidal extension invading only strap
• T4: Includes gross extrathyroidal extension into major neck
structures
– T4a: Gross extrathyroidal extension invading subcu-
– T4b: Gross extrathyroidal extension invading prevertebral
Tumour >4 cm limited to the thyroid
muscles (sternohyoid, sternothyroid, thyrohyoid or
omohyoid muscles) from a tumour of any size
aneous sof
t
recurrent laryngeal nerve from a tumour of any size
fascia or encasing carotid artery or mediastinal vessels
from a tumour of any size
t tissues, larynx, trachea, oesophagus or
Fig. 37.28: TIRADS imaging
• Hemithyroidectomy (if done for solitary nodule) may
reveal histological surprise with orphan Annie eyed
nuclear and psammoma bodies (calcified clumps of
cells with the papillary projections).
• CECT scan: It is routinely not done. Indications are:
Advanced lesions to know the distorted anatomy of
neck, infiltration into carotid sheath, retrosternal
extension/doubtful fixity.
Primary tumour (pT) for medullary thyroid carcinomas:
• TX–T3: Definitions are similar to the above
• T4: Advanced disease
– T4b: G
– T4a: Moderately advanced disease; tumour of any size
with gross extrathyroidal extension into the nearby tissues
of the neck, including subcut
trachea, oesophagus or recurrent laryngeal nerve
– T4b: Very advanced disease; tumour of any size with
extension toward the spine or into nearby large blood
vessels, invading the prevertebral fascia or encasing the
carotid artery or mediastinal vessels
Regional Lymph Node (pN)
• NX: Regional lymph nodes cannot be assessed
• N0: No evidence of regional lymph node metast
• N1: Metastasis to regional nodes
– N1a: Metastasis to level VI or VII (pretracheal, paratracheal,
prelaryngeal/Delphian or upper mediastinal) lymph nodes;
this can be unilateral or bilateral disease
– N1b: Metastasis to unilateral, bilateral or contralateral
lateral neck lymph nodes (levels I, II, III, IV or V) or
retropharyngeal lymph nodes
Distant Metastasis (M)
• M0: No distant metastasis
• M1: Distant metastasis
aneous soft tissue, larynx,
asis
Section II • General Surgery
418
Manipal Manual of Surgery
AJCC Prognostic Stage Grouping
Differentiated Thyroid Cancer
Age at diagnosis <55 years
Stage I: any T any N M0
Stage II: any T any N M1
Age at diagnosis 55 years
Stage I: T1 N0 / NX M0
T2 N0 / NX M0
Stage II: T1 N1 M0
T2 N1 M0
T3a / T3b any N M0
Stage III: T4a any N M0
Stage IVA: T4b any N M0
Stage IVB: any T any N M1
Medullary Thyroid Cancer
Stage I: T1 N0 M0
Stage II: T2 N0 M0
T3 N0 M0
Stage III: T1-3 N1a M0
Stage IVA: T4a any N M0
T1-3 N1b M0
Stage IVB: T4b any N M0
Stage IVC: any T any N M1
Anaplastic Thyroid Cancer
Stage IVA: T1–T3a N0 / NX M0
Stage IVB: T1–T3a N1 M0
T3b any N M0
T4 any N M0
Stage IVC: any T any N M1
Treatment
It can be discussed under three headings. Treatment of
the primary, treatment of the secondaries in the lymph
nodes and suppression of TSH.
I. Treatment of the Primary: Papillary Carcinoma
Thyroid without L
ymph Nodes. Stage I
(A) Total thyroidectomy, (B) Lobectomy and (C) Radioremnant ablation.
Indications for total thyroidectomy
• Age older than 45 years
• Contralateral nodules
• Prior irradiation
• Familial—differentiated thyroid carcinoma (DTC)
• DTC >1 cm in size
• Extra thyroidal extension
• Regional/local metastasis
A. Total thyroidectomy is the treatment of choice. It
means removal of the entire thyroid gland (Fig. 37.29).
No role for prophylactic lymph node dissection of
central compartmental nodes—level 6.
Advantages
• Easy to detect and treat residual or metastatic
disease—Dose of radioiodine 30–100 mCi.
• Easy to assess recurrence by thyroglobulin level
estimation.
• Eliminates contralateral occult cancer (multifocal in
80% patients).
• Eliminates re-surgery.
• Eliminates risk of recurrence, thus improving
survival.
• TSH suppression can be done.
Aims or Goals of Treatment of
Papillary Carcinoma Thyroid
• Excise primary tumour → Total thyroidectomy
• Remove clinically significant/palpable lymph node →
Functional neck dissection (no prophylactic neck
dissection)
• Minimal complications of surgery—preserve internal
jugular vein, accessory nerve.
• Once surgery is done—stage the disease
• Postoperative radioablation for residual thyroid tissue
(usually it is present).
• Long-term follow-up with ultrasound of the neck and
thyroglobulin for recurrence.
• Postoperative supplementary and suppressive dose of
thyroxine.
• Look for metastasis.
Section II • General Surgery
Disadvantages
• Total thyroidectomy has high complication rates such
as RLN paralysis, permanent hypothyroidism,
permanent hypoparathyroidism, etc.
• Recurrence in opposite lobe is only 5% which means
in 95% of the cases, removal of the opposite lobe is
unnecessary.
• Even if it occurs later, since it is not dissected at the
time of initial surgery, the lobe can be removed easily.
Fig. 37.29: Total thyroidectomy—in majority of cases
Thyroid Gland
419
• Tumour multicentricity has a little prognostic signi-
ficance. Thus in a few selected cases, lobectomy can
be done.
B. Lobectomy (hemithyroidectomy) means removal of
one lobe and entire isthmus (Fig. 37.30).
Fig. 37.30: Lobectomy—low-risk groups (hemithyroidectomy)
Indications for lobectomy
• Papillary carcinoma thyroid (PCT) less than 1 cm
(called microcarcinoma)—no clinically palpable
nodes, no extrathyroid extensions.
Advantages of lobectomy
• No hormone replacement
• No hypoparathyroidism
• Need not test thyroid function regularly.
II. Treatment of Papillary Carcinoma Thyroid with
Secondaries in the L
ymph Nodes (Figs 37.31 to 37.33)
• This is therapeutic not prophylactic lymph nodes
dissections. At surgery, one has to carefully look for
central compartment nodes—for enlargement. If
palpable and enlarged, they should be removed. If
nodes are enlarged in the anterior triangle, they are
dissected and removed en bloc along with fat and
fascia. This is called functional block dissection
(Berry picking means removal of enlarged lymph
nodes only. It is no longer followed).
• Level 2, 3, 4 and 5 nodes are removed when they are
enlarged.
• Structures, such as internal jugular vein, sterno-
mastoid muscle, accessory nerve are not removed
because lymph nodes are slow growing and they
rarely spread/outside the capsule of the lymph node.
However, in exceptional cases of papillary carcinoma
with infiltration to these structures, there should not
be hesitation to remove these structures, this is called
lateral neck dissection. In children, prophylactic/
direct lymph node dissection is done.
C. Radio remnant ablation: After surgery, thyroxine is
not given for a period of 4 weeks. Patient should be
hypothyroid and TSH is around 30 mU/L. At this stage,
radioisotope scan is done to look for residual thyroid
gland. Even after total thyroidectomy, it is possible
that some part of thyroid tissue may be present near
the trachea esophageal groove or Berry ligament area.
This needs to be ablated with 50 to 150 mCi of radioiodine.
• To avoid hypothyroidism for 4 weeks, patients can
be given T
and restarted quickly. Dose of T
because it acts quickly and it can be stopped
3
is 40–60 mg/day. It
3
is very costly; not freely available.
Fig. 37.31: Papillary carcinoma
thyroid in an 18-year
patient with lymph node metastasis at levels 2,3,4 and 6. This
patient was diagnosed as nonspecific lymphadenitis for about 1
month with various antibiotics
-old young
37.32 37.33
Figs 37.32 and 37.33: Functional neck dissection is done for papillary carcinoma thyroid.
Routine central compartment dissection is not required. Figure shows vagus nerve, carotid
artery and internal jugular vein. Sternocleidomastoid is retracted. All these structures are
preserved. Hence, the name functional neck dissection. Observe bluish colour lymph nodes
at surgery and specimen of lymph nodes. (Courtesy: Dr Gabriel Rodrigues, Professor,
Department of Surgery, Dr Suresh BP, Assistant Professor, Department of Surgery, KMC,
Manipal).
Section II • General Surgery
420
Manipal Manual of Surgery
III. Suppression of the TSH
• This is an important aspect in the postoperative
period because papillary carcinoma is a TSH dependent tumour. To prevent the patient developing
hypothyroidism in the postoperative period and to
suppress TSH, thyrotoxine (T4) 100 to 200 micrograms
are given. This need to be monitored—increase or
decrease depending upon the levels of TSH and toxicity.
• Failure of suppression of TSH to a level <0.1 mU/L
suggests inadequate dose of thyroxine or noncompliance. Summary of papillary carcinoma thyroid
is given in Key Box 37.22.
Key Box 37.22
Summary of Papillary Carcinoma Thyroid
Most common histological type of thyroid cancer (60
to 65%).
Most often it is multifocal (80%).
Commonly it spreads by lymphatic spread.
Psammoma bodies are suggestive and nuclear groov-
ing is diagnostic of papillary carcinoma of thyroid.
Most often it presents as solitary nodule and with or
without lymph node metastasis.
Most commonly done procedure for papillary carci-
noma thyroid is total thyroidectomy with or without
functional neck dissection.
Radioactive iodine ablation and thyroxine 0.2 mg are
important post-operative.
Most of the patients (>95%) have 10-year survival rate.
Fig. 37.34: Management protocol of papillary carcinoma
Management Protocol of Papillary Carcinoma of
the Thyroid (Fig. 37.34)
Figure 37.34 depicts management protocol of papillary
carcinoma of the thyroid.
FOLLICULAR CARCINOMA
• Incidence: Constitutes 17% of cases (Key Box 37.23).
• Follicular adenoma 20% are malignant and 80% are
benign.
Aetiology
• Follicular carcinoma usually arises in a multinodular
goitre, especially in cases of endemic goitre. It should be
suspected when MNG starts growing rapidly (Fig.
Key Box 37.23
Incidence of Thyroid Malignancy
Papillary carcinoma 60–65%
Follicular carcinoma 15–20%
Anaplastic carcinoma 10–12%
Medullary carcinoma 5–10%
Others 10%
Section II • General Surgery
37.35).
Fig. 37.35: Follicular carcinoma thyroid—clinically suspected—
ultrasound showed microcalcification—FNAC revealed follicular
. She underwent total thyroidectomy. Final report was
cells
follicular carcinoma thyroid
Pathology
Depending upon the property of invasion, it is classified
into:
• Non-invasive which means minimal invasion.
• Invasive refers to angioinvasion and capsular
invasion, necessary for the diagnosis of follicular
carcinoma of thyroid. The tumour cells line the blood
vessels and get dislodged into the systemic circulation
producing secondaries in the bones. Microscopically,
most of the tumours are well encapsulated (Fig. 37.36
).
Thyroid Gland
Fig. 37.36: Follicular carcinoma thyroid showing well-
differentiated follicles invading the capsule and capsular veins.
Please remember follicular carcinoma cannot be diagnosed
by FNAC but by histopathology only (Courtesy: Prof Laxmi Rao,
Head, Department of Pathology, KMC, Manipal)
421
– Vascular and pulsatile
– Underlying bony erosion may be present.
Clinical Presentation
• It can present as a solitary nodule. The diagnosis is
considered only after an ultrasound scan reveals
some features of malignancy, such as microcalcifica-
tion. Peak age group is around 40 years.
• In case of long-standing multinodular goitres, if the
goitre is rapidly growing, hard or has restricted
mobility, follicular carcinoma can be considered.
• Metastasis in the flat bones: The only clinical situation
wherein a follicular carcinoma can be considered as
the diagnosis is when a patient with a thyroid swelling
presents with metastasis in the bone in the form of
bony swelling or pathological fractures. Commonly,
secondaries develop in the flat bones such as skull,
ribs, sternum, vertebral column because the flat bones
retain red marrow for a longer time. When bony swell-
ing is obvious and thyroid is not palpable clinically,
it is called occult primary site (Figs 3
7.37 to 37.40).
• The clinical features of secondary in the skull are:
They are rapidly growing.
–
– They are warm.
Fig, 37.39: This lady presented
with thyroid swelling of 5 years’
duration with swelling in the
scalp and sternum of 2 months
duration. Bony swellings were
painful—it was a case of
follicular carcinoma of thyroid
with multiple bony metastasis:
Lady with three swellings
Key Box 37.24
Fig. 37.40: Ulcerated secon-
dary in the scalp bone from
follicular carcinoma thyroid.
See dilated veins in the neck.
No other differential diagnosis
in such patients. Initially it was
diagnosed as lipoma. Neck
examination for thyroid enlargement was not done.
Reasons why Bone Metastasis Grow Rapidly from
Follicular Carcinoma Thyroid—Seed and Soil Hypothesis
1. Tumour cells secrete angiogenesis compounds
2. Tumour cells secrete factors which enhance bone
resorption
3. Increase production of IL-1, IL-6 which increase
osteolytic activity
4. Maliganant cells synthesise adhesive molecules
because of which they get attached to bone matrix
Investigations
• High frequency ultrasound scan is done (Figs 37.41
and 37.42) to demonstrate nature of the nodule,
whether solid or cystic and to guide FNAC. It should
be remembered that FNAC cannot differentiate a
follicular adenoma from follicular carcinoma. Hence,
if FNAC reports as follicular cells, overtreat the patient
by total thyroidectomy. Some follow with frozen
section and proceed. If frozen section is follicular
carcinoma, total thyroidectomy is done. No role for
open biopsy except in inoperable advanced carcinoma
thyroids specially anaplastic carcinoma thyroid.
Fig. 37.37: Secondary deposit in
the sternum in a patient who
underwent near-total thyroidectomy for follicular carcinoma
5 years back
Fig. 37.38: Chest X-ray
showing osteolytic lesion in
the left clavicle
Open biopsy is also not taken in cases of parotid tumors for
the fear of damage to fascial nerve, in testicular tumors for the
fear of dissemination of the tumor.
Section II • General Surgery
422
Fig. 37.41: Ultrasound revealing recurrence (nodules) in both
lobes of the thyroid gland (Courtesy: Dr Chandrakanth Shetty,
Professor, Department of Radiodiagnosis, KMC, Manipal)
Manipal Manual of Surgery
• Whole body bone scan-I131 is done to rule out
multiple osseous metastasis. Flat bones are
commonly involved. They retain the red marrow for
a longer period. Because of increased angiogenesis,
secondaries grow more rapidly than primary tumors
in follicular carcinoma thyroid. A few differential
diagnoses of secondaries in the skull bones are given
below in the Key Box 37.25.
• Whole-body MRI (91% diagnostic accuracy) to be
superior to PET-CT (78% diagnostic accuracy) in
detecting bone metastases. MRI is excellent in
detecting marrow component and osseous and extra
skeletal extent of the disease.
Key Box 37.25
Causes of Secondary in the Skull
1. Follicular carcinoma of thyroid
2. Renal cell carcinoma
3. Hepatocellular carcinoma
4. Prostatic carcinoma
5. Bronchogenic carcinoma
Fig. 37.42: Colour Doppler showing the relationship of the gland
to major vessels of the neck (Courtesy: Dr Chandrakanth Shetty,
Professor, Department of Radiodiagnosis, KMC, Manipal)
• Plain X-ray of the involved bone can reveal osteolytic
lesions (Fig. 37.43 ).
Section II • General Surgery
Fig. 37.43: Erosion of skull bone
• CT scan in appropriate cases such as very large
tumours adherent to trachea, vessels in the neck and
mediastinal extension (Fig. 37.44).
• When primary is not found, bone biopsy is required
to find out the site of the primary.
Fig. 37.44: CT neck and chest showing the large mass
displacing the carotid artery, internal jugular vein thrombosis
and mediastinal lymph nodes. Lymph nodes were cleared after
sternotomy
A patient with a diagnosis of ‘lipoma of the scalp’ was
posted for excision in the prone position. As the chief
surgeon scrubbed and was about to paint the part, he could
see the pulsatile nature of the swelling, which he had
missed in the outpatient department. Fortunately, it was not
excised. A needle was introduced and frank blood was
aspirated. Surgery was cancelled. X-ray skull showed osteolytic lesion. She had a small thyroid nodule (Fig. 37.40).
Thyroid Gland
423
TREATMENT OF FOLLICULAR CARCINOMA OF THYROID
I. Treatment of the Primary
• Situation I: When a patient has enlarged thyroid
gland and scalp swelling, total thyroidectomy is the
treatment of choice. Secondaries do not take up the
131
radioisotope (
I) in the presence of primary tumour.
Hence, lobectomy or hemithyroidectomy should not
be done.
• Situation II: A patient undergoes subtotal thyroidec-
tomy for MNG and final report is follicular carcinoma
thyroid. In such cases, it is better to do completion
thyroidectomy within 7 days or after 4 weeks.
• If done, within 7 days, or after 4 weeks, it is relatively
easy to do. Between 7 days and 4 weeks, the inflammatory process would have produced dense fibrosis,
chances of injuring RLN, parathyroids are high.
• Situation III: A patient with solitary nodule—high
suspicion of malignancy after sonography and FNAC
reported as follicular cells, it is better to go ahead
with total thyroidectomy.
II. Treatment of the Metastasis
• After total thyroidectomy, a whole body bone scan
is done to look for metastasis in the bone. Bone metastasis occur in about 15% of patients with follicular
carcinoma thyroid. A single secondary can be treated
by oral radioiodine therapy, followed if necessary by
external radiotherapy depending upon the response
of the tumour. Multiple secondaries, if present, can
best be detected by CT-PET scan and are treated by
oral radioiodine therapy. Dose may be around 100
to 200 micro Ci.
Key Box 37.26
Hürthle Cell Carcinoma
More aggressive follicular carcinoma
More than 75% malignant cells
More chances of lymphatic spread
More chances of distant spread
More chances of mortality
• They secrete thyroglobulin.
• Even if Hürthle cell adenoma is well encapsulated, it
is potentially malignant.
131
• It does not take up
131
respond to
I ablation.
I. Hence, it is less likely to
• Higher mortality (20% at 10 years).
99m
•
Tc—sestamibi scan can detect Hürthle cell
carcinoma.
Criteria to Diagnose Hürthle Cell Carcinoma
• Capsular/vascular invasion, distant metastasis.
• Higher chance of spread to lymph nodes compared
to follicular thyroid carcinoma.
• Higher chances of spread to distant sites also.
Treatment
• Total thyroidectomy is the treatment of choice. In
many cases of Hürthle cell carcinoma, lymph nodes
are enlarged. Hence, modified radical neck dissection
is done (MRND).
• TSH suppression and follow-up are regularly
required.
III. Postoperative Thyroxine
• In the postoperative period, patients should receive
thyroxine 100 to 200 mg/day to suppress TSH and
to supplement thyroxine. The dose may have to be
adjusted based on toxicity (tachycardia) and level of
TSH.
Prognosis: 15% mortality in 10 years.
HÜRTHLE CELL CARCINOMA
• Hürthle cell carcinoma is a variant of follicular
carcinoma (Key Box 37.26). It is more aggressive than
follicular carcinoma.
• These tumours are defined by the presence of
more than 75% of follicular cells having oncocytic
features.
• Tumour contains sheets of eosinophilic cells packed
with mitochondria.
All Hürthle cell neoplasms are almost malignant and all
adenomas are almost follicular. In all suspicious solitary
nodules of follicular cell origin, it is better to overtreat them by
total thyroidectomy than relying upon the frozen section, to
avoid second surgery.
Follow-up of patients with papillary and follicular
carcinoma thyroid—differentiated thyroid cancer
• Serum thyroglobulin (Tg): Thyroid is the only organ
which produces thyroglobulin. Levels greater than
10 ng/ml in patients receiving replacement thyroxine
therapy indicates presence of metastasis. Hence,
assess the serum Tg response to injected recombinant
human TSH every year. In thyrotoxicosis and
thyroiditis, thyroglobulin levels may be increased
(Key Box 37.27).
• Ultrasonography or MRI scans of the neck for
localisation of residual or recurrent tumour.
Section II • General Surgery