STN- update.pptx

MANAGEMENT OF
SOLITARY
THYROID NODULE
CAPE COAST
TEACHING
HOSPITAL
DEPARTMENT OF
SURGERY
PRESENTER:
STEPHEN ADU-DANQUAH
(RESIDENT)

OUTLINE
1.Introduction
2.Definition
3.Anatomy
4.Physiology
5.Epidemiology
6.Assessment
7.Investigation
8.Treatment
9.Conclusion

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.

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

ANATOMY
• Butterfly shaped
• 7-25 g in African
• 15-25g in Caucasian
5

• INNERVATION AND ARTERIAL
SUPPLY

BLOOD SUPPLY

VENOUS SUPPLY

LYMPHATICS

EMBRYOLOGY
3rd week of gestation
10 – 12th begin function

HISTOLOGY

PHYSIOLOGY

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

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

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

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)

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)

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)
EPIDEMIOLOGY

EPIDEMIOLOGY
• Year 2022 :
Total patients with goitre: 312
Males 32 :10.3 %
Females 280: 89.7%
New cases : 27.8%
Old cases : 72.1 %

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

CAUSES

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,

• 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

DIAGNOSTIC APPROACH
• INITIAL :
 HISTORY AND PHYSICAL EXAM
 SERUM TSH
 THYROID USG
• SUBSEQUENT
• TSH Low : Thyroid scintigraphy
• TSH normal or High: FNAC

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)

• 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

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

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

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

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

EYE SIGNS
• Exophthalmos
• von graef’s sign
• Dalrymple sign
• Joffroy’s sign
• Moebius sign
• stellwag’s sign
• Kocher’s sign

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.

FACTORS SUGGESTING MALIGNANCY
IN A THYROID NODULE

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)

Cont.
• Serum calcitonin elevated in
Medullary Carcinoma Of thyroid
• 24 hr urine for Metanephrines and
Catecholamines
• Serum Calcium to exclude
hyperparathyroidism

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 )

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.

ECHOGENICITY/ FOCI, SHAPE,
MARGIN, COMPOSITION

SCORING AND
CLASSIFICATION
• TR1: 0 points - benign
• TR2: 2 points - not suspicious
• TR3: 3 points - mildly
suspicious
• TR4: 4-6 points - moderately
suspicious
• TR5: ≥7 points - highly
suspicious

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
FNA

RECOMMENDATIONS
– follow up: 1, 2, 3 and 5 years
FNA
– annual follow up for up to 5
years
– ACR Thyroid Imaging
Reporting and Data System
(ACR TI-RADS)

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)

MRI is more accurate in
distinguishing Recurrent or
Persistent thyroid Tumour from
postoperative Fibrosis.

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

Cont.
• Specificity 72 – 100%
• Sensitivity 65 – 98 %

RESPECTIVE MALIGNANCY
RISK WITH EACH CATEGORY
(BETHESDA SYSTEM)
1. Non diagnostic
2. Benign < 1%
3. Atypia of undetermined
Significance /Follicular lesion
of undetermined significance
(AUS /FLUS) 5- 10 %
4. Follicular neoplasm/
suspicious 20 – 30%

Cont
5. Suspicious for Malignancy 50
– 75 %
6. Malignant – 100 %

INTRANUCLEAR
CYTOPLASMIC
INCLUSION

LIMITATIONS OF FNAC
• False positive results (Difficulty in
interpreting Cytology)
 Hashimoto thyroiditis
 Graves Disease
 Toxic Nodules
• Cannot distinguish Follicular
adenoma from Carcinoma

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

Advantage of Technetium:
• A. required in smaller dose
• B. less expensive
• C. less radiation exposure
• D. shorter ½ life

• 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

REPORT OF
SCINTIGRAPHY

COLD NODULE
HOT NODULE

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)

• Second scan after TSH
suppression
• Uptake of radioiodine low or
undetectable in non-
autonomous , but persist in
autonomous tissue

TREATMENT
• Toxic/hyperthyroidic patients
should be rendered Euthyroid
• Carbimazole, Methimazole,
Propylthiouracil
• Propranolol
• Lugol’s iodine (5% iodine +
10% potassium iodide)

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

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

NODULE
• If FNAC report says medullary
total thyroidectomy with
bilateral neck nodal dissection
including central compartment
is done.

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.

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
total thyroidectomy with
bilateral neck nodal dissection
including central compartment
is done.

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

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).

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.

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

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)

• 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.
Cont.

• The American Thyroid
Association (ATA) guidelines
for thyroid nodule 2009,
Revised in 2013

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.

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

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)

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

• 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
REFERENCES

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