thyroid nodule

1. Dr. SANJAY MAHARJAN
2ND Yr Resident, ENT-HNS
MTH
APPROACH TO
THYROID NODULE

2. INTRODUCTION
• Discrete lesion within thyroid gland that is
radiologically distinct from surrounding parenchyma
• Noted by patient, or as an incidental finding
• May be
Palpable or impalpable,
Functioning or nonfunctioning

3. EPIDEMIOLOGY:
• Framingham study
Ages  35 – 59
Women  6.4 %
Men  1.5 %
• Prevalence increases with
Age
Exposure to ionizing
radiation (Nodule in
radiated patient: 35-40%
cancer)
• Pregnancy increases risk

4. • Represents a
wide spectrum
of disease
• Most are,
 Colloid nodules,
 Adenomas
 Cysts,
 Focal thyroiditis
• Only 5-6% are
malignant

6. CLINICAL ASSESSMENT: HISTORY AND
PHYSICAL EXAMINATION
• History:
• Younger and older patients (m >40yrs and F >50yrs) more
likely to have malignant thyroid nodule
• Children may present with more advanced disease
• Incidence F>M, but aggressiveness M>F
• Rapid growth of a preexisting or new thyroid nodule
(hemorrhage into cyst / carcinoma)
• Throat or neck pain (hemorrhage into benign nodule, rarely
as/w carcinoma)

7. • Compressive or invasive symptoms like
Voice change
Hoarseness
Dysphagia
Dyspnea
• Symptoms of hyperthyroidism and hypothyroidism should be
explored
• Family history
• H/o previous head and neck radiation exposure
• H/o medullary carcinoma, pheochromocytoma, or
hyperparathyroidism (MEN syndromes)

8. • Physical examination:
• Careful palpation of thyroid
(solitary or dominant nodule in
multinodular gland )
• Firm nodule  2-3 times
increased risk of carcinoma
• Substernal extension estimated
by relationship of inf aspect of
mass to clavicle
• Thoracic inlet obstruction by
Pemberton maneuver

9. • Physical findings suggesting possible malignancy include
Vocal cord paralysis
Cervical lymphadenopathy (also in Hashimoto thyroiditis,
Graves disease, or infection)
Fixation of nodule to surrounding tissues

10. INVESTIGATION
• Lab investigations :
 CBC, ESR for inflammatory or infectious thyroiditis
 TFT, Most patients are euthyroid
 TSH is an independent risk factor for predicting malignancy
 TPO antibodies in pts with high TSH (Hashimoto's
thyroiditis)
 Serum calcitonin is elevated in medullary carcinoma of
thyroid
 24-hour urine for metanephrines and catecholamines
 Serum calcium to exclude hyperparathyroidism

11. • Radiography :
 Not routinely
done
 May show
 Tracheal
deviation or
compression
 Pulmonary
metastasis
 Calcifications

12. • Ultrasound scanning :
• Noninvasive and inexpensive
• Detect non palpable nodules
• Differentiate between cystic and
solid nodules
• Identify hemiagenesis and
contralateral lobe hypertrophy
misdiagnosed as thyroid nodule
• Detect cervical nodes that may
contain early clinically occult
metastatic disease

13. • Features as/w low risk of
thyroid Ca
• Features as/w Increased risk
of thyroid Ca

17. • Computed tomography (CT) and MRI :
• Usually unnecessary
• Useful in determining
Substernal extension
Identifying cervical and mediastinal adenopathy
Evaluating relationship of thyroid lesion to adjacent neck strs
(trachea and esophagus)
• MRI is more accurate in distinguishing recurrent or
persistent thyroid tumor from postoperative fibrosis

18. • FNAC :
• Emerged in 1970s
• Procedure of choice in evaluation of thyroid nodules
• Minimally invasive
• Improved diagnostic accuracy
• Higher malignancy yield at the time of surgery
• Significant cost reductions
• Specifity : 72 – 100% , sensitivity : 65 – 98%

19. Bethesda System for Reporting Thyroid
Cytopathology

20. Respective risk of malignancy associated with each
diagnostic category (Bethesda System) is
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%
5. Suspicious for malignancy - 50-75%
6. Malignant - 100%

21. • Thyroid nodule diagnostic FNA is recommended for:
A) Nodules > 1cm in greatest dimension with high suspicion
sonographic pattern
B) Nodules > 1 cm in greatest dimension with intermediate
suspicion sonographic pattern
C) Nodules > 1.5cm in greatest dimension with low suspicion
sonographic pattern
D) Nodules > 2cm in greatest dimension with very low
suspicion sonographic pattern

27. • Limitations of FNAC :
• False-positive results (difficulties in interpreting cytology)
Hashimoto thyroiditis
Graves disease
Toxic nodules
• Cannot distinguish follicular adenoma from carcinoma

29. • Thyroid scintigraphy :
• Should be performed in patients with low serum TSH
• Utilizes one of iodine radioisotopes (usu. I123) or
technetium-99m pertechnetate
• Others : Thallium-201 scan, Gallium-67, Tc-99m sestamibi
• Most benign and virtually all malignant thyroid nodules
concentrate both radioisotopes less avidly

30. • 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 sub-sternal
extension

31. • Hyper functioning - ‘‘HOT’’
tracer uptake is greater than
surrounding thyroid (~5%
malignant)
• Iso-functioning - ‘‘WARM’’-
tracer uptake is equal to
surrounding thyroid (~10%
malignant)
• Non-functioning - ‘‘COLD ’’
uptake less than surrounding
thyroid (~20% malignant)

33. • Indeterminate :
• Superimposition of abnormal nodular tissue and normally
functioning thyroid tissue
• Should be evaluated by FNA
• Can be also be assessed by suppression scanning
Thyroid hormone sufficient to suppress TSH secretion
(2 mcg/kg for 10 days)
Second scan once TSH suppression documented
Uptake of radioiodine low or undetectable in non-
autonomous, but persist in autonomous tissue

37. RATIONAL APPROACH TO MANAGEMENT
OF A THYROID NODULE :

39. THANK YOU