3. INTRODUCTION
• “Anxiety induced by the fear of malignancy
in solitary thyroid nodule (STN) against a
background of common benign nodular
disease generates the diagnostic dilemma
for the clinicians and make its management
controversial.
• With the availability of current diagnostic
techniques, it is now possible to have
selective approach to management of STN
by identifying those patients likely to have
malignancy and avoiding thyroidectomy in
majority of patient with benign disease ” –
Anil Haripriya, Ass. Prof.
4. DEFINITION
• Discrete lesion within thyroid
gland that is radiologically
distinct from Surrounding
parenchyma
• May be palpable or impalpable
• Functioning or nonfunctioning
• Importance of STN lies in the
risk of malignancy compared
with other thyroid swellings
(10-15 %) and it being toxic.
Tuesday, May 16, 2023 4
15. EPIDEMIOLOGY
FRAMINGHAM STUDY:
• Age 35 – 59
• Women 6.4%
• Men 1.5 %
• Prevalence increases:
Age
Exposure to Ionising radiation
Nodule in radiated patient 35-40 % risk of
cancer
In an Autopsy study: 37 – 57 %
had thyroid nodules
Pregnancy increases risk
Tuesday, May 16, 2023 15
16. EPIDEMIOLOGY
• Study in china among
6,985,956 participants
showed overall prevalence of
thyroid nodule was 36.9%
• Females = 44.7%
• Males = 29.9%
• Prevalence increased > 25yrs
Tuesday, May 16, 2023 16
17. EPIDEMIOLOGY
• Jena et al in a study in India
“malignancy in solitary thyroid
nodule”
46.2% of STN were malignant
compared to that of MNG 22.5%
• In a study in Nigeria:
1 out of 13 cases of STN (7.6%)
were malignant compared to 24 of
160 cases of MNG (15%)
Edino et al
Tuesday, May 16, 2023 17
18. EPIDEMIOLOGY
• Study in 225 patients who
underwent thyroid surgery:
27.1 % had STN
• Malignancy rate 34.4 %
(Keh et al, journal of laryngology
and otology, 129, 7)
Tuesday, May 16, 2023 18
19. EPIDEMIOLOGY
• In another study:
• Prevalence of asymptomatic
thyroid nodule (320
participants) - 11.3%
• ATN were common in the left
lobe - 69%
• Predominantly solitary- 64%
(Assin North District, Central
Region – Morna et al, 2020)
Tuesday, May 16, 2023 19
20. CCTH
• Year 2019 - 2021: Total number of
gotre: 350
• Males : 37
• Females 313
• Toxic single nodule: 4 cases:
mean age 48 yrs
(Maddy et al)
Tuesday, May 16, 2023 20
EPIDEMIOLOGY
21. EPIDEMIOLOGY
• Year 2022 :
Total patients with goitre: 312
Males 32 :10.3 %
Females 280: 89.7%
New cases : 27.8%
Old cases : 72.1 %
Tuesday, May 16, 2023 21
22. EPIDEMIOLOGY
2 out of 6 documented STN
were actually STN.
Rest were diffused and MNG
• They never reported for
review with FNAC and TFT.
• One was 26 yrs and the other
36yrs
• Both females
Tuesday, May 16, 2023 22
24. STUDY ON HISTOPATHOLOGY
• Karim et al
• 32.5% cases were diagnosed as
colloid goiter
• 28.75% cystic
• 10% thyroiditis - among them
3.75% as granulomatous thyroiditis
5% as lymphocytic thyroiditis
1.25% dequervain thyroiditis,
Tuesday, May 16, 2023 24
25. • 6.25% as follicular neoplasm
• 1.25% as hurthle cell adenoma
• 3.3% as papillary carcinoma,
• 1.25% as medullary carcinoma
• 0.33% anaplastic carcinoma
• 0.33% NHL as suspicious smear
Tuesday, May 16, 2023 25
26. DIAGNOSTIC APPROACH
• INITIAL :
HISTORY AND PHYSICAL EXAM
SERUM TSH
THYROID USG
• SUBSEQUENT
• TSH Low : Thyroid scintigraphy
• TSH normal or High: FNAC
Tuesday, May 16, 2023 26
27. HISTORY
HOW NODULE IS FOUND
• Incidental finding on diagnostic
work up (usg – 19-35% Dean et
al)
• Self detection
• Surveillance
• Work up for symptoms of
hyper/hypo thyroidism
• Palpation with physical exam (2-
6% Dean et al)
Tuesday, May 16, 2023 27
28. • HISTORY
Younger and older Pateints (M>
40, F >50) more likely to have
malignant thyroid nodule.
Children may present with more
advanced disease
Rapid growth in a preexisting or
new thyroid nodule may indicate
Haemorrhage into cyst or
Malignancy
Tuesday, May 16, 2023 28
29. CONT. HISTORY
• Throat or neck pain: Haemorrhage into
benign nodule; rarely with Carcinoma
• Compressive or invasive Symptoms:
Voice changes, Hoarseness, Dysphagia ,
Dyspnoea
• Symptoms of hypothyroidism/
Hyperthyroidism:
Hypo: weight gain in spite of poor appetite, facial puffiness,
loss of hair, lethargy, poor memory, constipation,
oligomenorrhea
Hyper: weight loss in spite of good appetite, heat
intolerance, excessive sweating. CNS: Irritability, insomnia,
tremors of hands, muscle weakness
Tuesday, May 16, 2023 29
30. cont. HISTORY
• Family History: thyroid dx
• History of previous head and neck
Radiation Exposure
• History of (MEN syndromes)-
Medullary Carcinoma of thyroid,
Pheochromocytoma, Or
hyperparathyroidism
Tuesday, May 16, 2023 30
31. PHYSICAL EXAMINATION
• Careful palpation of thyroid
(solitary nodule or dominant
nodule in multinodular goitre)
• Firm nodule: 2-3x increased risk
of Carcinomas
• Substernal Extension: Estimated
by the relationship of the inferior
aspect of the mass to the clavicle
Tuesday, May 16, 2023 31
32. PHYSICAL EXAMINATION
• Pemberton manoeuvre- Thoracic
inlet Obstruction.
• FINDINGS SUGGESTIVE OF
MALIGNANCY
Vocal cord paralysis
Cervical Lymphadenopathy (also in Hashimoto
thyroiditis ,graves disease or infection )
• Fixation of nodule to Surrounding
tissues
Tuesday, May 16, 2023 32
35. WHO CLASSIFICATION OF
THYROID swelling
• Grade 0- no visible or
palpable thyroid swelling.
• Grade I- no visible but
palpable
• Grade II- there is visible and
palpable thyroid swelling.
• Grade III- Large thyroid
swelling.
Tuesday, May 16, 2023 35
37. INVESTIGATION
• CBC, ESR for inflammatory or
infectious thyroiditis
• TFT most Patients are Euthyroid
(94.5% Jena et al)
• TPO antibodies in patients with
high TSH (Hashimoto thyroiditis)
Tuesday, May 16, 2023 37
38. Cont.
• Serum calcitonin elevated in
Medullary Carcinoma Of thyroid
• 24 hr urine for Metanephrines and
Catecholamines
• Serum Calcium to exclude
hyperparathyroidism
Tuesday, May 16, 2023 38
40. ULTRASOUND SCAN
• Currently the initial imaging modality of
choice for detection and characterization
of the thyroid gland
• It reports varied prevalence of
asymptomatic thyroid nodule ranging 20
-67 % (Morna et al, 2020 )
Tuesday, May 16, 2023 40
41. ULTRASOUND SCAN
ADVANTAGES
• Noninvasive and inexpensive
• Detect nonpalpable nodules
• Differentiate between Cystic and
solid nodules.
• Identify Hemiagenesis and
contralateral lobe hypertrophy
misdiagnosed as thyroid nodule
• Detect Cervical nodes which may
contain early clinically occult
Metastatic disease.
Tuesday, May 16, 2023 41
45. RECOMMENDATIONS
• TR1: no FNA required
• TR2: no FNA required
• TR3: ≥1.5 cm follow up, ≥2.5 cm
FNA
– follow up: 1, 3 and 5 years
• TR4: ≥1.0 cm follow up, ≥1.5 cm
FNA
Tuesday, May 16, 2023 45
46. RECOMMENDATIONS
– follow up: 1, 2, 3 and 5 years
• TR5: ≥0.5 cm follow up, ≥1.0 cm
FNA
– annual follow up for up to 5
years
– ACR Thyroid Imaging
Reporting and Data System
(ACR TI-RADS)
Tuesday, May 16, 2023 46
47. CT and MRI
• Useful in determining substernal
extension
• Identifying Cervical and
Mediastinal Lymphadenopathy
• Evaluating Relationship of thyroid
Lesion to adjacent Neck structures
(Trachea and Esophagus)
Tuesday, May 16, 2023 47
48. MRI is more accurate in
distinguishing Recurrent or
Persistent thyroid Tumour from
postoperative Fibrosis.
Tuesday, May 16, 2023 48
49. FNAC
• Emerged in 1970
• Procedure of choice in Evaluating
Thyroid nodules
• Minimally invasive
• Improved Diagnostic Accuracy
• Higher malignancy yield at the
time of surgery
• Significant cost reductions
Tuesday, May 16, 2023 49
59. LIMITATIONS OF FNAC
• False positive results (Difficulty in
interpreting Cytology)
Hashimoto thyroiditis
Graves Disease
Toxic Nodules
• Cannot distinguish Follicular
adenoma from Carcinoma
Tuesday, May 16, 2023 59
60. THYROID
SCINTIGRAPHY
• Performed in patients with low
serum TSH
• Utilises one of iodine radioisotope
(Usually I – 123) or technetium -
99m Pertechnetate)
• Others: Thallidium -201 scan,
Gallium 67 , Tc 99m Sestamibi
Tuesday, May 16, 2023 60
61. Advantage of Technetium:
• A. required in smaller dose
• B. less expensive
• C. less radiation exposure
• D. shorter ½ life
Tuesday, May 16, 2023 61
62. • DISADVANTAGE:
• 1. only tests iodine transport
(I123 also organification of I)
• 2. hot nodules require I123
scanning for confirmation
• 3. Does not penetrate
sternum – not useful in
substernal extension
• 4. Only IV forms available,
unlike iodine which has oral
Tuesday, May 16, 2023 62
65. INDETERMINATE THYROID
NODULE
• Superimposition of abnormal
nodular tissue and normally
functioning thyroid tissue
• Should be evaluated by FNAC
• Can be also assessed by
suppression scanning
• Thyroid hormone sufficient
to suppress TSH secretion
(2mcg /kg for 10 days)
Tuesday, May 16, 2023 65
66. • Second scan after TSH
suppression
• Uptake of radioiodine low or
undetectable in non-
autonomous , but persist in
autonomous tissue
Tuesday, May 16, 2023 66
69. TREATMENT
• Toxic/hyperthyroidic patients
should be rendered Euthyroid
• Carbimazole, Methimazole,
Propylthiouracil
• Propranolol
• Lugol’s iodine (5% iodine +
10% potassium iodide)
Tuesday, May 16, 2023 69
70. TREATMENT- BENIGN
NODULE
• Nontoxic benign nodule is treated
with observation without any
therapy
• Solitary toxic nodule needs initial
antithyroid drugs and then
radioactive iodine therapy ;
occasionally surgery is done –
hemithyroidectomy.
• Colloid nodule can be observed or
hemithyroidectomy is done for
cosmesis or just in pain or
increase in size
Tuesday, May 16, 2023 70
71. TREATMENT – MALIGNANT
NODULE
• Risk of malignancy in follicular
lesion of undetermined
significance (FLUS) is 10%.
Total thyroidectomy is
indicated here.
• If FNAC comes as papillary
carcinoma of thyroid, then
total or near total
thyroidectomy is done
Tuesday, May 16, 2023 71
72. TREATMENT – MALIGNANT
NODULE
• If FNAC report says medullary
carcinoma of thyroid, then
total thyroidectomy with
bilateral neck nodal dissection
including central compartment
is done.
Tuesday, May 16, 2023 72
73. TREATMENT – MALIGNANT
NODULE
• If FNAC report says follicular
adenoma, then
hemithyroidectomy is done. If
histology report says follicular
carcinoma (capsular and
vascular invasion), then
completion total
thyroidectomy is done.
Tuesday, May 16, 2023 73
74. TREATMENT – MALIGNANT
NODULE
• If there is a nodule in the
isthmus, isthmectomy is done
with excision of part of
adjacent lateral lobes
• If FNAC report says medullary
carcinoma of thyroid, then
total thyroidectomy with
bilateral neck nodal dissection
including central compartment
is done.
Tuesday, May 16, 2023 74
75. TREATMENT
INDETERMINATE NODULE
• If FNAC shows follicular
neoplasm, then
hemithyroidectomy, paraffin
section confirmation for
capsular and vascular
invasion; completion
thyroidectomy in 7–14 days;
later radioactive iodine
therapy is used
Tuesday, May 16, 2023 75
76. TREATMENT INDETERMINATE
NODULE
• If FNAC shows suspicious variety,
then repeat FNAC is done.
• If it is also suspicious then
hemithyroidectomy is done;
frozen section biopsy is done to
confirm if it is papillary carcinoma;
if so, total thyroidectomy with
ipsilateral central node neck
dissection is carried out. (Frozen
section is not suitable for follicular
neoplasm).
Tuesday, May 16, 2023 76
77. TREATMENT -
NONDIAGNOSTIC NODULE
• Cyst that recurs and repeat
FNAC also becomes
nondiagnostic then
hemithyroidectomy is the
better option especially if
nodule is more than 4 cm in
size and or in high-risk group.
• Repeat FNAC becomes
diagnostic in 50% of initial
nondiagnostic.
Tuesday, May 16, 2023 77
78. INDICATIONS FOR SURGERY
• All malignant nodules.
• Follicular neoplasm.
• Symptomatic thyroid nodule
• Cystic nodule which does not
disappear following three times
aspiration.
• Non functioning or hyper
functioning nodule.
• Complex cyst – both solid and
cystic components
• For cosmetic purposes
Tuesday, May 16, 2023 78
79. What are the types of
thyroidectomy?
• i. Hemithyroidectomy: Removal of
one lobe and entire isthmus. It is
usually done in benign disease of
one lobe.
• ii. Subtotal thyroidectomy: Removal
of all thyroid tissue, keeping 8 grams of
functional thyroid tissue at lower pole (4
grams may be kept at each lobe and it
is measured by the size of pulp of
patient's thumb)
Tuesday, May 16, 2023 79
80. • iii. Partial thyroidectomy- Removal of
thyroid tissue in front of trachea after
mobilization. It’s commonly done in non
toxic multinodular goiter. It’s role is
controversial.
• iv. Near total thyroidectomy- Rim of
thyroid tissue to be kept at lower pole of
one or both sides to save recurrent
laryngeal nerve and parathyroid glands.
• v. Total thyroidectomy: Entire thyroid
gland is removed. Usually done in a case
of papillary, follicular carcinoma and
medullary carcinoma of thyroid.
Tuesday, May 16, 2023 80
Cont.
81. • The American Thyroid
Association (ATA) guidelines
for thyroid nodule 2009,
Revised in 2013
Tuesday, May 16, 2023 81
83. CONCLUSION
With advent of current diagnostic
technique and with their appropriate
use in diagnosis of STN, it is now
possible to have a selective
approach to management of STN by
identifying the patient likely to have
malignancy and avoiding
thyroidectomy in majority of patient
with benign diseases who can be
given conservative medical
treatment.
Tuesday, May 16, 2023 83
84. Post presentation
questions
• 1. Why FNAC unable to diagnose
Medullary Carcinoma
• Ans: insufficient specimen for histology.
Only cells aspirated.
• 2. Why FNAC is contraindicated in hot
nodules?
• Ans : to not cause thyrotoxicosis
• 3. Duration for Pemberton sign?
• Ans : up to a minute
Tuesday, May 16, 2023 84
85. REFERENCES
• Up to date
• SRB P - 465
• Gateway to success in surgery , p
182-184
• Reiners et tal, thyroid disorders in
the working population:
ultrasound screening, 2004,
14:926
• (Keh et al, journal of laryngology
and otology, 129, 7)
Tuesday, May 16, 2023 85
86. REFERENCES
• Karim et al, A study on evaluation of
solitary nodular thyroid lesions by FNAC
and its histopathologicalBangladesh
Journal of Medical Science Vol. 18 No.
04, 789 October 19
Tuesday, May 16, 2023 86
87. • Rice, co. incidence of nodules in
the thyroid, 1932, 24:505
• Pubmed, Arch Surg. 1932: 24:505
• Dean DS, Gharib H. Epidemiology of
thyroid nodules. Best Pract Res Clin
Endocrinol Metab. 2008;22(6):901–11.
• Pubmed
• Google
• Baja
Tuesday, May 16, 2023 87
REFERENCES
Editor's Notes
Bow tie shaped
Pretracheal fascia covering anterior and lateral surfaces
Each lateral lobe strapped to trachea by sternohyoid, sterno thyroid, omohyoid
Posterior border in intimate relationship with superior and inferior parathyroid glands which lie within pretracheal fascia
Innervation: Recurrent laryngeal nerve (left recurrent laryngeal nerve arises anteriorly at the level of the arch of aorta and loops posteriorly back up the neck, the right recurrent laryngeal nerve arises anteriorly at the level of T1-T2 , loops under the right subclavian artery traveling posteriorly back up)passes between the branches of inferior thyroid artery , pierces pretracheal fascia and innervating all intrinsic muscles of the larynx. to enter thyroid gland injury causes hoarseness
The superior laryngeal nerve (AKA - Amelita Galli-Curci nerve) is related to the superior thyroid artery which divides into intrernal and external branches after piercing the pre-tracheal fascia supplying crico thyroid muscle. Injury affects high pitch notes
The external branch of the nerve is subject to injury during mobilization of superior thyroid artery.
Superior pole vessels should be ligated close to superior pole to avoid injury to nerve
Paratracheal lymph nodes
Deep cervical lymph nodes
Thyroid gland develops from endodermal cells in foramen caecum located between first and second branchial arches around tuberculum impar. Formation of thyroglossal diverticulum and then migration down to the neck. There is maturation during migration in isthmus and lateral lobes. Forming thyroglossal duct which later obliterates
Thyroid hormone synthesis includes the following steps: (1) iodide (I-) trapped by the thyroid follicular cells ; (2) diffusion of iodide to the apex of the cells; (3) transport of iodide into the colloid; (4) oxidation of inorganic iodide to iodine by thyroid peroxidase and incorporation of iodine into tyrosine residues within thyroglobulin molecules in the colloid; (5) combination of two DIT molecules to form tetraiodothyronine (T4) or of MIT with DIT to form T3; (6) uptake of thyroglobulin from the colloid into the follicular cell by endocytosis, fusion of the thyroglobulin with a lysosome, and proteolysis and release of T4, T3, DIT, and MIT; (7) release of T4 and T3 into the circulation; and (8) deiodination of DIT and MIT to yield tyrosine. T3 is also formed from monodeiodination of T4 in the thyroid and in peripheral tissues.
T4: thyroxine; T3: triiodothyronine; DIT: diiodotyrosine; MIT: monoiodotyrosine.
TSH – Anterior pituitary
T 3 – more active, less in amount
T 4
Potentiates action of catecholamines
Stimulate gut motility
Enhance lipogenesis, lipolysis
Normal function of CNS
On cytology 52 (32.5%) cases were diagnosed as colloid goiter, 46 (28.75%) as colloid goiter with cystic change, 16(10%) as thyroiditis - among them 6(3.75%) as granulomatous thyroiditis, 8(5%) as lymphocytic thyroiditis, 2(1.25%) as dequervain thyroiditis, 10 (6.25%) as follicular neoplasm, 2(1.25%) as hurthle cell adenoma, 5(3.3%) as papillary carcinoma, 2 (1.25%) as medullary carcinoma, 1(0.33%) anaplastic carcinoma and 1(0.33%) NHL as suspicious smear.`
During surveillance: during routine follow ups, mass could be palpable
Pemberton sign is used to evaluate venous obstruction in patients with goiters. Sign is positive when bilateral arm elevation causes facial plethora (cyanosis, congestion and respiratory distress)
Von graef sign - Lid lag of upper lid on downward gaze
Dalrymple sign - lid retraction ,
Joffroy’s sign – lack of wrinkling,
Stellwag’s sign – staring look = Incomplete and infrequent blinking
Moebius sign - lack of convergence on looking near object
Kochers sign - Increased lig retraction with visual fixation
MEN medullary thyroid carcinoma: prophylactic thyroidectomy
TSH is an independent risk factor for predicting Malignancy
to achieve standardization of diagnostic terminology, morphologic criteria, and risk of malignancy for reporting of thyroid FNA, in 2007, the National Cancer Institute (NCI) organized the NCI Thyroid Fine Needle Aspiration State of the Science Conference which proposed a 6-tier system and named it The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC)
Psammoma body = Papillary Carcinoma
Psammoma bodies are round, microscopic calcifications (collections of calcium salts).
Orphan Annie eyes = Papillary Carcinoma
Microfollicles in syncytia with nuclear atypia = Follicular lesion
Eosinophilic oxyphilic cell with abundant cytoplasm = Hurthle cell lesion
Immuno staining for calcitonin = Medullary Carcinoma
Carbimazole = It acts by blocking thyroid hormone synthesis. Carbimazole also suppresses the autoimmune process in thyroid in Grave’s disease.
Methimazole = Methimazole is not used in 1st trimester pregnancy as it may cause cloacal and scalp abnormalities
Propylthiouracil = It acts by blocking thyroid hormone synthesis as well as by blocking peripheral conversion of T4 to T3. It also decreases the thyroid autoantibody levels. It can be given for hyperthyroidism in children and in pregnancy, lactation.
Propranolol = It is a beta blocker, which is used as an antithyroid drug
Lugol’s iodine (5% iodine + 10% potassium iodide) = It decreases the vascularity of the gland and makes it more firm and easier to handle during surgery. Dose is 10–30 drops/day (minims) for 10 days prior to surgery
or the amount of tissue in trachea oesophageal group.
