2. THYROID BIOMARKERS
• Thyroid stimulating hormone.
Its actions on the TSH receptor on thyroid follicular cells as a part of the hypothalamic-
pituitary-thyroid axis.
Normal value 0.4 to 4.12 mIU/L.
• T3 and T4.
Serum T3.
• Normal levels-1.5-3.5 nmol/L
• Most(80%)T3 is produced by deiodination of T4 in the liver, muscle, kidney and anterior
pituitary.
• T3 is 3to4 times more potent thanT4.
3. • The half-life of T3 is approximately 24 hours, whereas half-life of T4 is
about 7 days.
• FreeT3(3to9pmol/L) is most useful in confirming the diagnosis of early
hyperthyroidism.
Serum T4
• Normal levels-55 to 150 nmol/L.
• In euthyroid state, T4 is the predominant hormone produced by the
thyroid.
4. Thyroid autoantibodies.
• The measurement of serum thyroid autoantibodies is useful in
the diagnosis of various autoimmune thyroid diseases.
• The three most commonly measured autoantibodies are anti-
TPO (TPOAb), anti-Tg (TgAb), and anti-TSH receptor (TRAb).
• More than 90% of the patients with Hashimoto's thyroiditis
and 80% of patients with Graves' disease have antibodies
which are called as 'LATS' (long acting thyroid stimulator).
5. Thyroglobulin.
• The most important use of this test is to monitor
patients after total thyroidectomy for well-
differentiated carcinoma.
• It is not nomrally released into circulation in large
amount but increases suddenly in thyroiditis, Graves'
disease or toxic multinodular goitre (MNG).
6. Calcitonin.
• Calcitonin is a 32–amino acid protein secreted by the
parafol- licular C cells.
• Serum calcitonin is the most sensitive biomarker for
the detection and surveillance of medullary thyroid
cancer (MTC), which is a malignancy of the
parafollicular C cells.
7. THYROID IMAGING
• NECK ULTRASOUND.
• Neck ultrasonography is the preferred modality for routine
radio- graphic evaluation of the thyroid gland.
• It offers the most accurate visualization and allows for the
concomitant ability to perform percutaneous fine-needle
aspiration.
• Advantages of ultrasound include the fact that it is
noninvasive and portable for the clinic and it is not associated
with radiation exposure.
8. TI-RADS
•Thyroid Imaging Reporting and Data System
(TI-RADS), stratifies nodule characteristics into
five risk levels, from TR1 (benign) to TR5 (highly
suspicious).
•Categorization has five features,
•Nodule composition, echogenicity, shape,
margin, and echogenic foci.
9.
10.
11. • FNA CYTOLOGY.
• FNA biopsy is the most accurate and cost-effective invasive
procedure in the workup of thyroid nodules.
• For all thyroid nodules, FNA has a mean sensitivity of over
80% and a mean specificity of over 90%.
• National Cancer Institute developed a consensus for cytologic
terminology known as the Bethesda System for Reporting
Thyroid Cytopathology updated in 2017.
12. • Representative cytologic features of thyroid fine-
needle aspiration specimens arranged according to
the Bethesda classification for prediction of
malignancy.
• CATEGORY I: nondiagnostic/unsatisfactory.
13. CATEGORY II: BENIGN COLLOID NODULE WITH BLAND-
APPEARING FOLLICULAR CELLS ARRANGED IN A
MACROFOLLICULAR PATTERN AND ABUNDANT COLLOID IN THE
BACKGROUND.
14. CATEGORY
III: ATYPIA OF UNDETERMINED SIGNIFICANCE; FOLLICULAR CELLS SHOW
NUCLEAR ENLARGEMENT OF MOST NUCLEI WITH OCCASIONAL
INTRANUCLEAR GROOVES.
15. CATEGORY IV: FOLLICULAR NEOPLASM WITH HIGHLY CELLULAR ASPIRATE
COMPOSED OF UNIFORM FOLLICULAR CELLS ARRANGED IN
MICROFOLLICLES.
16. CATEGORY V: SUSPICIOUS FOR PAPILLARY THYROID CANCER; THESE
REPRESENTATIVE
MICROFOLLICULAR GROUPS SHOW NUCLEAR ENLARGEMENT AND PALE
17. CATEGORY VI: PAPILLARY THYROID CANCER DEMONSTRATING A LARGE
SHEET OF NEOPLASTIC CELLS WITH ENLARGED OVAL “ORPHAN ANNIE EYE”
NUCLEI; MULTIPLE INTRANUCLEAR PSEUDOINCLUSIONS ARE ALSO
PRESENT.
18. • Nuclear Scintigraphy.
• Thyroid scintigraphy is performed using either
technetium-99m pertechnetate or a radiolabeled
iodine nuclide (typically 123I or 131I).
• Nodular disease can be classified into whether there is
increased focal uptake (the so-called “hot” nodule) or
not (the “cold” nodule).
19.
20. • Cross sectional imaging.
• Computed tomography (CT) or magnetic resonance
imaging (MRI) scans can be useful adjuncts to
ultrasound.
• These modalities are helpful particularly for two
scenarios: substernal (intrathoracic) goiter and
advanced thyroid cancer
22. THYROIDECTOMY
Definition: it is a removal of all or part of thyroid gland
• Indications :
As therapy for patient with thyrotoxicosis.
To treat benign or malignant thyroid tumor.
To treat pressure symptoms such as respiratory disetress or dyspnea or
dysphagia.
Cosmotic purpose.
To establish difinitive treatment of thyroid mass specially when
cytological results is indeterminate.
24. HEMITHYROIDECTOMY
• It involves removal of one lobe plus entire isthmus is
removed.
• It is performed in benign disease involving one lobe.
• Also done in follicular carcinoma involving one lobe.
• Other indication:
A)solitary toxic or non toxic nodule .
B)thyroid cyst.
25.
26. SUBTOTAL THYROIDECTOMY
• Subtotal thyroidectomy, in which 3 to 5 g of thyroid
tissue is left, is less commonly performed today.
• The rationale for these lesser-extent lobar resections
has been to protect the RLN and blood supply to
the parathyroids, as well as to preserve thyroid
function.
27.
28. NEAR TOTAL THYROIDECTOMY
•Near-total thyroidectomy, in which less
than 1 g of remnant thyroid tissue is
left at the ligament of Berry, is also
commonly performed.
•Mostly done in papillary carcinoma
thyroid.
32. PROCEDURE
•Position: under general anasthesia patient is put
on supine position,with neck hyperextended
with sandbag under shoulder ,table tilt 15degree
head to reduce venous congestion.(rose
position).
• Skin is prepped from chin to the upper thorax.
33.
34. INCISION
•Transverse skin crease incision is placed 2-3
cm above the sternal notch about 8cm long
extending to lateral border of
sternocleidomastoid muscle.
•The scapel with size 15 blade is slanted to
divide skin and platysma.
•Hemostasis controlled with electrocuttary.
35.
36. SEPARATING STRAP MUSCLES AND EXPOSING THE
ANTERIOR SURFACE OF THYROID
•The fascia between strap muscles
(sternohyoid,sternothyroid,and
omohyoid)is divided,along midline and
muscle retracted laterally.
•Pre tracheal fascia is opened vertically to
expose the thyroid.
37.
38. IDENTIFY THE MIDDLE THYROID VEIN
•The thyroid gland is rotated medially using
surgeon finger .
•The middle thyroid vein identified which is
then ligated.
•This permit further mobilization of the
gland.
39.
40. SUPERIOR POLE OF THYROID
• Superior pole is dissected.
• Identify the superior thyroid artery, close to
superior pole of the thyroid parenchyma and ligate
it.
• Dissection is done in avascular plane between
upper pole of the gland and crico-thyroid muscle to
avoid trauma of external branch of superior
laryngeal nerve entering crico-thyroid.
41.
42. IDENTIFY THE SUPERIOR
PARATHYROID GLAND
• Location:in the posterior position at the level of
upper 2/3 of the thyroid and approximately 1cm
above and behind the crossing point of recurrent
laryngeal nerve and inferior thyroid artery.
• It is orange yellow in colour.
• The gland must remain in situ with blood supply
intact.
43.
44. IDENTIFY THE POSTERIOR
PARATHYROID
•Location :between lower pole of thyroid and
isthmus, below and in front of crossing .
•Care must be given to preserve it in situ to
avoid damage it is inferior thyroid artery
supplying both glands.
45. CAPSULAR LIGATION OF INFERIOR
THYROID ARTERY
•It is a branch of thyrocervical trunk .
•Ligation done at capsular level, at the
lower pole of thyroid gland.
46.
47. IDENTIFY RECURRENT LARYNGEAL
NERVE
• Should be identified with dissection of entire
course .
• Recurrent laryngel nerve is located in Riddles
triangle.
• Superiorly: inferior thyroid artery.
• Medially: trachea.
• Laterally:common carotid artery.
48.
49. DISSECTION OF THYROID
•Berrys ligament :define the posteriolateral
attachment of thyroid gland .
•Blunt dissection can be used to further expose
this fascia ,then with scalpel transect the
ligament.
•Often minimal amount of thyroid tissue left near
the entrance of recurrent laryngeal nerve into
50.
51. CLOSURE
• Absolute hemostasis.
• Suction drain to thyroid bed (beneath strap
muscle).
• Close loosely in layer with absorbable sutures.
• Close skin with suture or clips.
• Check vocal cord on extubation by direct
laryngoscope.
52.
53. COMPLICATION
•Hemorrage :occurs due to slipped ligature of
superior thyroid artery or small veins.
• It causes tachycardia, hypotension,
breathlessness, severe stridor.
•Treatment:ligation of bleeder under general
anasthesia.
54. • Respiratory obstruction: occur due to:
• Hematoma.
• Laryngeal edema (commonest).
• Bilateral recurrent nerve palsy.
• Treatment :evacuation of hematoma.
55. • Recurrent laryngeal nerve palsy:
• May be unilateral or bilateral.
• Unilateral: mostly asymptomatic only some change in voice which
gradually become normal ,no need specific treatment.
• Bilateral: change in voice and severe dyspnea and stridor lead to
respiratory arrest .
• Treatment :emergency tracheostomy.
56. • Hypoparathyroidism : May be Temporary due to
vascular spasm of parathyroid gland .
• Occur in 2nd to 5th post operative day.
• It present with muscle weakness and convulsion
• Treatment is calcium gluconate iv 8 hourly. Later oral
calcium supplement.
57. • Thyrotoxic crises (thyroid storm):
• Occur in thyrotoxic patient not well prepared for surgery.
• Other causes infection, DM, pre-eclampsia.
• Features:
• Severe dehydration, circulatory collapse,
hypotension,hyperpyrexia.
• Tachypnea, palpitation, cardiac failure.
• GIT : vomiting or diarrhea.
