Download Solitary nodule of thyroid - Chennai City Branch Of ASI

Solitary
nodule of
thyroid
Prof.P.Ragumani.
MS.
MMC & RG
GGH.Ch.3
• A discrete swelling in an otherwise
impalpable gland is termed
isolated or solitary.
• Dominant swelling in a gland is
clinical evidence of generalised
abnormality in the form of a
palpable contralateral lobe or
generalised mild nodularity.
• About 70% of discrete thyroid
swellings are clinically isolated
and about 30% are dominant
• Some 15% of isolated swellings prove to
be malignant, and an additional 30–40%
are follicular adenomas.
• The remainder are non neoplastic, largely
consisting of areas of colloid
degeneration, thyroiditis or cysts
• Solitary palpable nodules are about four
times more prevalent in women than in
men
The prevalence of thyroid nodules detected on palpation
(broken line) or by ultrasonography or post-mortem
examination(solid line)
of
12’). The risk of cancer in a thyroid swelling can
be expressed as a factorof 12. The risk is greater
in isolated vs. dominant swellings, solid vs.cystic
swellings and men vs. women.
Presenting complaints
• Swelling in front of neck
• Dysphagia
• Dyspnoea
• Hoarseness of voice
• Hypothyroid/ hyperthyroid
features
•
SYMPATHETIC TRUNK – Horner’s syndrome
Enophthalmos
Miosis
Anhydrosis
Ptosis
•
Palpate for thrill
BERRY’S SIGN – malignant thyroid engulfs the
carotid sheath completely hence pulsation not felt.
• PALPATION OF CERVICAL
NODES.
most solitary thyroid nodules are benign
and can be classified as
•Adenomas
•Colloid nodules,
•Congenital abnormalities,
•Cysts
•Infectious nodules
• lymphocytic or granulomatous nodules
• hyperplasia
FOLLICULAR ADENOMA
• Solitary
• well-defined, intact capsule
Follicular adenoma of the thyroid.
A solitary, well-circumscribed nodule
is seen
Microscopically
• arranged in uniform follicles that contain
colloid .
• The neoplastic cells are uniform, with welldefined cell borders.
• Occasionally, the neoplastic cells acquire
brightly eosinophilic granular cytoplasm
(oxyphil or Hürthle cell change)
1. even benign follicular adenomas on
occasion exhibit focal nuclear
pleomorphism
atypia
prominent nucleoli (endocrine
atypia)
Papillary change is not a typical
feature of adenomas and, if
present, should raise the suspicion
of an encapsulated papillary
carcinoma
follicular adenoma. Welldifferentiated follicles resemble
normal thyroid parenchyma
Follicular carcinoma of the
thyroid. A few of the
glandular lumens contain
recognizable colloid.
•
The hallmark of all follicular adenomas is
the presence of an intact well-formed
capsule encircling the tumor.
• Careful evaluation of the integrity of the
capsule is therefore critical in the
distinction of follicular adenomas from
follicular carcinomas, which demonstrate
capsular and/or vascular invasion .
Lab investigations
• THYROID PROFILE
serum TSH
units/ml
TOTAL T4
TOTAL T3
Free T4
Free T3
Thyroglobulin
35microgram/lit
• SERUM CALCIUM
8-10nmol/l
– 0.5 – 5micro
50- 150nanomol/lit
1.5- 3.5nanomol/lit
- 12-28picomol/lit
- 3-9picomol/lit
- <1-
Thyroid imaging
X ray chest and neck
1. retrosternal thyroid
extension
2.thyroid calcification
3.bony or mediastinal LN
4. lung metastases
5.Tracheal deviation and
compression
AP CXR with large
retrosternal goitre
ultrasound
• Non invasive and no radiation exposure
• Information about size,shape,extend and
multicentricity of gland
• Distinguishing from solid from cystic ones
• To asses cervical lymphadenopathy
• To guide FNAC
ultrasound
Large left lobe with solid and
Cystic components
Dominant solid nodule in right lobe
• 47-year-old woman
with thyroid nodule.
Transverse
ultrasound image of
thyroid shows 7-mm
well-defined, longer
than wide
(anteroposterior
diameter, 7 mm;
transverse diameter,
4 mm) isoechoic
nodule (arrow).
• Fine-needle
aspiration biopsy of
the nodule was
confirmed papillary
carcinoma with
extrathyroidal
invasion.
Haemorrhagic thyroid
cyst
• papillary thyroid
carcinoma with
BRAFV600E mutation.
On transverse
sonogram, 1.2-cm
irregular-shaped,
markedly
hypoechoic nodule
(arrows) with
peripheral
calcification is
noted in isthmic
portion of thyroid
gland. Sonography
diagnosed nodule as
malignancy.
Sonography-guided
fine needle
aspiration and total
thyroidectomy
confirmed papillary
thyroid carcinoma
with extracapsular
invasion.
CYTOLOGY
Parameters for cytologic
assessment of solitary nodules
•
•
•
•
•
•
•
•
•
(1) cellularity,
(2) colloid content,
(3) acinar formation,
(4) papillary formation,
(5) intranuclear cytoplasmic inclusions,
(6) nuclear grooves,
(7) marginal vacuoles,
(8) Hürthle cells,
(9) presence of various inflammatory
cells,
• (10) cellular atypia.
FNAC
• Investigation of choice for discrete thyroid
swelling
• Excellent patient compliance
• Simple and quick to perform
• Safe, efficacious and cost effective
• Provides pre op diagnosis and therefore
planning
FNAC
TECHNIQUE
• 23 guage
needle
• Multiple passes
• Ideally from
periphery of
lesion
• Reaspirate after
fluid drawn
• Immediately
smeared and
fixed
• Papanicolaou
stain common
FNAC
RESULTS
• Thy1
non
diagnostic
• Thy2
nonneoplastic
• Thy3
follicular
• Thy4
suspicious
of
malignancy
• Thy5
malignant
Thy2 aspiration cytology. NonThy3 aspiration cytology. Follicular
neoplastic appearances with scantyneoplasm showing increased
normal follicular cells together with cellularity with a follicular pattern.
colloid
Thy5 aspiration cytology. Papillary
carcinoma with
typical cellular variability and nuclear
inclusions.
• FNAC of
papilary
carcinoma of
thyroid showing
intracytoplasmi
c inclusions(
orphan annie
eyes and
psomama
bodies)
FNAC
LIMITATIONS
• Hypocellular aspirates may be
observed in cystic nodules, or they
may be related to biopsy technique.
• The absence of malignant cells in an
acellular or hypocellular specimen
does not exclude malignancy.
• Inability to reliably distinguish a
benign follicular neoplasm from a
malignant neoplasm.
• Aspirates may be required from
multiple sites of the nodule to
improve sampling.
FNNAC
• Fine needle non aspiration cytology or
cytopuncture or fine needle capillary
sampling
• Principle of capillary suction of fluid in to a
thin channel
• 23 guage needle is used
• Used in cytological assesment of thyroid,
breast and lymph nodes
ADVANTAGES
• Easy to perform
• Amount of cellular yield was found to be
better
• Cellular degeneration is lesser
• Smears with better maintenance of
architexture
• Yield diagnostically superior specimen.
FNNAC smear of follicular neoplasm
showing hypercellularity, less trauma
and better retained architecture in
comparison to FNAC smear
FNNAC smear of colloid goitre showing
less blood in the background in
comparison to FNAC smear
RADIONUCLIDE IMAGING
• For the assesment of thyroid function
• Demonstrates the function of thyroid
nodule in comparision to the surrounding
structures
hot- excess uptake(5%)
warm-normal uptake
cold- no uptake(20%)
• imaging done with gamma camera
Radioactive iodine scan of the thyroid,
with the arrow showing an area of
decreased uptake, a cold nodule.
•Hot
nodule
showing
increased
activity
than the
•Warm nodule
normal uptake
Radioisotopes
•
•
•
•
•
•
Tc99m
I 131
I 123
I 125
Thallium 201
Gallium 67
Iodine is trapped and organified
Tecnitium trapped but not organified
Tc99m
• Most commonly used radionuclide(99-mass
number; m-metastable)
• Administered IV
• Pure gamma ray emitter
• Short half life
• Images can be obtained quickly
• Administered as pertechnate(Tco4).
I 123
• Shorter half life (12-13 hrs)
• Obtain quicker image
• Low dose radiation
• Good choice for lingual thyroids
and subternal goitre
I 131
• Longer duration (8 days)
• Emits beta rays
• Used for thyroid carcinoma
• screening modality of choice for
the evaluation of distant
metastasis.
THALLIUM 201
• Expensive, role poorly defined
• Can detect (but not treat) mets.
• Not trapped or organified- mechanism
unclear
• Advantages
not necessary to be off thyroid
replacement
patients with large body iodine pool
or hypofunctioning thyroid
OTHER IMAGING AGENTS
• Tc-99m sestamibi
• Tc-99m pentavalent DMSA
• Radioiodinated MIBG
developed for medullary (APUD
derivative)
Radiolabelled monoclonal antibodies
CT
For detecting regional
&distant metasasis
from
thyroid cancer
to detect retrosternal
involvement
• MRI
diagnosis of
cervical LN
metastasis
FDG PET
To screen for
metastasis in
thyroid cancer
Fused computerised tomography
and positron emission tomography
scans showing a left-sided thyroid
ENT examination
• To assess the status of vocal
cords preoperatively
Benign Thyroid Nodule: factors
favouring
• Family history of Hashimoto's thyroiditis
• Family history of benign thyroid nodule or
goiter
• Symptoms of hyperthyroidism or
hypothyroidism
• Pain or tenderness associated with a
nodule
• A soft, smooth, mobile nodule
• Multi-nodular goiter without a
predominant nodule (lots of nodules, not
one main nodule)
• "Warm" nodule on thyroid scan (produces
normal amount of hormone)
Malignant Nodule:
• Age less than 20
•
•
•
•
•
•
•
•
•
•
Age greater than 70
Male gender
New onset of swallowing difficulties
New onset of hoarseness
History of external neck irradiation during
childhood
Firm, irregular, and fixed nodule
Presence of cervical lymphadenopathy
(swollen, hard lymph nodes in the neck)
Previous history of thyroid cancer
Nodule that is "cold" on scan (shown in
picture above, meaning the nodule does not
make hormone)
Solid or complex on an ultrasound
TREATMENT APPROACH FOR SNT
TFT
ELVATED
NORMAL
I 131
USG
HOT
DIFFUSE OR -VE
CYST
I 131/ SURGERY
FOLLOW& Rx
ASPIRATE
SOLID
FNAC
POSITIVE
NEGATIVE
SURGERY
FOLLOW UP
MALIGNANCY
SURGERY
INDETERMINATE
RE FNAC
FOLLICULAR
SURGERY
BENIGN
SUPPRESSION
MODES OF TREATMENT
ANTITHYROID
DRUGS
RADIO IODINE
THERAPY
SURGERY
ANTITHYROID DRUGS
CARBIMAZOLE
PROPYLTHIOURACIL


Mainly used to bring the patient to euthyroid state in
toxic nodule and toxic MNG.
Soon after starting radio iodine therapy until the
effects of radio iodine are seen.
Mechanism of action:
Inhibit iodination and coupling
Carbimazole is converted to methimazole.
Dose:
Initially carbimazole 10mg TDS until the patient
becomes euthyroid.
Maintenance dose: 5mg TDS
Advantages of propylthiouracil:
• Lower risk of transplacental transfer
• Inhibits peripheral conversion of T4 to T3
• Can be used in pregnancy and lactation
Side effects:
Reversible granulocytopenia
Skin rashes
Fever
Peripheral neuritis
Agranulocytosis
Aplastic anaemia
Vasculitis
Propranolol
For quick preparation of patient for surgery
Alleviates catecholamine response of thyrotoxicosis.
Inhibits peripheral conversion of T4 to T3
Dose: 40mg in 3 divided doses
Contraindications: Asthma
Heart Block
Congestive cardiac failure
Diabetes mellitus
Nadalol 160 mg OD can be given
Lugol’s Iodine
5% iodine + 10% potassium iodide
Mechanism of action:
Increases colloid
Tamponade effect on vessels
Firm gland (less vascular)
Dose: 10 drops for last 10 days before surgery
Administered by mixing with milk
RADIOACTIVE IODINE
Destroys thyroid tissue
Dose: I131 oral 5 millicurie
Indications:
primary thyrotoxicosis (>45yrs)
toxic nodule
relapse after surgery/ medical therapy
Adverse effects:
hypothyroidsm
increased risk of mutations, thyroid CA
Contraindications
Absolute
Pregnancy
Lactation
Relative
Young patient
Children
Ophthalmopathy
MNG with toxicosis
Effect of radio iodine starts
after 6 to 12 weeks.
Until then antithyroid drugs
are given.
SURGERY
Types:
1.Hemithyroidectomy:
Removal of one lobe + isthumus
Solitary nodule
Follicular adenoma
2.Subtotal thyroidectomy:
8gms of tissue, the size of pulp of finger is retained on
the lower pole on both sides and the rest is removed.
Multinodular goitre
Diffuse toxic goitre
3.Partial thyroidectomy:
Removal of thyroid tissue except in
tracheoesophagal groove.
4.Near total thyroidectomy:
Both lobes are removed except lower pole
5.Total thyroidectomy:
Entire gland is removed
Follicular CA
Medullary CA
6.Hartley Dunhill Operation:
Removal of one lobe with isthumus and
subtotal removal of opposite lobe.
7.Isthumusectomy:
When there is compression of trachea in
Anaplastic CA
Malignant lymphoma
Riedel’s thyroiditis
PREOPERATIVE PREPARATION
Thyrotoxicosis – Carbimazole 10mg TDS until the patient
becomes euthyroid.
Maintenance: 5mg TDS
Propranolol 40mg- 3 divided doses
Lugol’s iodine 10 drops for last 10 days before surgery
Anaesthesia: General anaesthesia
Position:
Supine. Hyperextension of neck with sandbag
under shoulder.
Head end tilted 15 degree up to reduce
venous congestion.
• Incision:
Kocher’s incision
Horizontal crease incision 2 finger breadth above
sternal notch from one sternomastoid to the other.
STEPS OF SURGERY
• Skin and platysma are incised.
• Upper flap is raised upto thyroid cartilage and lower
flap upto sterno clavicular joint.
• Deep fascia is opened by vertical incision.
• Strap muscles are retracted or cut.
• Pretracheal fascia is opened.
• Middle thyroid vein is ligated.
• Superior thyroid pedicle is ligated close to
the gland to avoid injury to external laryngeal nerve.
• Inferior pedicle is ligated
away from the gland to avoid
injury to recurrent laryngealN.
• Now the mobilised gland
is removed.
• Drain is placed and
wound is closed in layers.
During thyroidectomy, the recurrent
laryngeal nerve is at greatest risk for i
(1)
During thyroidectomy, the recurrent laryngeal nerve is at
greatest risk for injury (1) at the ligament of Berry,
(2) during ligation of branches of the inferior thyroid
artery, a (3) at the thoracic inlet
Non recurrent laryngeal nerve
Incidence 0.5-1.5%
Intraoperative photo of the recurrent
laryngeal nerve in the tracheoesophageal
groove (white arrow)
•COMPLICATIONS OF
THYROIDECTOMY
Haemorrhage
A tension haematoma deep to the cervical
fascia is usually due to reactionary haemorrhage
from one of the thyroid arteries;
This is a rare but desperate emergency
requiring urgent decompression by opening the
layers of the wound
Respiratory obstruction
Most cases are caused by
 laryngeal oedema
 trauma to the larynx
 by anaesthetic intubation
 surgical manipulation
This is very rarely due to collapse or
kinking of the trachea
(tracheomalacia
Recurrent laryngeal nerve paralysis
and voice change
RLN injury may be
unilateral or bilateral,
transient or permanent.
Superior laryngeal nerve
paralyis
Injury to the external branch of the superior laryngeal
nerve is more common because of its proximity to the
superior thyroid
artery.
This leads to loss of tension in the vocal cord with
diminished power and range in the voice.
Endoscopic thyroidectomy
SUTURELESS
THYROIDECTOMY
By using harmonic scalpel to
ligate supr & infr thyroid
vessels
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