solitary thyroid nodule

1. SOLITARY THYROID
NODULE

2. DEFINITIONS
• OLD :
In an otherwise normal gland, a single palpable
nodule in the thyroid on clinical examination.
• NEW :
A DISCRETE lesion /nodule, WITHIN the thyroid,
that is PALPABLY and/or RADIOLOGICALLY DISTINCT
from the surrounding thyroid parenchyma.
*5-15 % of all Solitary Thyroid Nodules = Thyroid Malignancy.

4. SOLITARY THYROID
NODULE
MULTI NODULAR
GOITRE
COLLOID
GOITRE

5. EPIDEMIOLOGY
• A palpable thyroid nodule is usually > 1 cm.
• It is more common in women (6.4%) than men (1.5%).
• The prevalence is
– 4% by palpation,
– 19 to 67% by ultrasound examination,

6. HISTORY
• Age and Gender
-Around 20 to 50% of solitary nodules in patients younger than 20 years are malignant.
-Pediatric thyroid carcinoma occurs in teenage years (mean 16) and in girls 5.6 times more
often than in boys.
-Beyond 70 years of age, malignancy is not common, but prognosis is worse when present.
-Risk of malignancy in men is twice that of women.
• Diet
-Patients from iodine-sufficient areas have a higher rate of malignancy than those from iodine-
deficient areas (5.3% vs 2.7%)*.

7. HISTORY
The thyroid nodule is often discovered incidentally during a clinical examination
– Rate of growth:
• Over hours with pain suggests hemorrhage into an existing nodule.
• Over weeks is more strongly associated with malignancy, and
• During levothyroxine therapy is especially suggestive of cancer.
• Sudden change in the size of a pre-existing nodule may indicate malignancy.

8. EXPOSURE TO RADIATION
• The risk is maximum after 20 to 30 years of exposure.
• Thyroid nodule + History of radiation = 40% Chance of Thyroid Cancer.
• Exposure to Radiation for Hodgkin’s Lymphoma / CA Breast
– 100 Rads- Thyroid nodules, Thyroid carcinoma
– >2000 Rads - Prevent thyroid neoplasm (Thyroid gland destroyed)

9. PHYSICAL EXAMINATION
• The thyroid gland and nodules within it move with swallowing.
• The size, site, shape consistency and presence of any other
palpable nodules should be noted.
– Nodule with firm consistency - autoimmune thyroid disease
– Stony hard consistency favors malignancy.
– Firm nodule along with fixity suggests invasion and may be
apointer toward malignancy

10. SUMMARY OF MALIGNANT CHARACTERISTICS
• Young patients (< 20 years) or old (> 70 years),
• Male sex,
• H/O external neck radiation during childhood or adolescence,
• Recent change in voice (RLN Involvement)
• Past family history of thyroid carcinoma.
• Enlarging Nodule (Size >4 cms)
• Firm to solid consistency nodule,
• Irregular shape,
• Fixation to underlying or overlying tissues,
• Suspicious regional lymphadenopathy.
• Family history of PTC, MTC, or MEN2

11. DIAGNOSTIC APPROACH
• To determine if
– Detrioration in function Or
– has risk of malignancy.

12. WORK UP OF A THYROID NODULE

14. FINE-NEEDLE ASPIRATION CYTOLOGY
• the most important diagnostic evaluation for a thyroid nodule.
• It is the safest, most cost-effective, and most reliable technique to
differentiate between benign and malignant diseases of the thyroid.
• FNACs reduces the number of thyroidectomies by half while doubling the surgical
confirmation of carcinoma.
• FNAC can be done with or without USG guidance. USG guided FNAC is more reliable,
rapid, accurate and safe.

15. FINE-NEEDLE ASPIRATION CYTOLOGY
• Sensitivity and specificity exceed 90 and 70%, respectively.
• Seeding is unlikely.
• The false negative rate = (1 - 5)% and is associated with cysts or nodules
• -smaller than 1 cm or
• - masses greater than 3 cm.

16. FNAC SPECIMENS
• 70% Benign,
• 5% Malignant,
• 10% Suspicious,
• 15% Unsatisfactory

17. USG GUIDED FNAC
Indicated if:
• Palpation-guided FNA is non diagnostic
• Complex (solid/cystic) nodule
• Palpable small nodule (<1.5 cm)
• Impalpable nodule
• Abnormal cervical L. nodes
• Nodule with suspicious US features

18. INDICATIONS FOR REPEAT FNA
• Follow-up of benign nodule
• Enlarging nodule
• Recurrent cyst
• Nodule >4 cm
• Initial FNA non-diagnostic.
• No shrinkage after T4 therapy

19. IMAGING THE THYROID

20. ULTRASONOGRAPHY
• Most sensitive test to detect lesions in the thyroid.
• Not indicated as screening test in general population.
Indicated in:
– Palpable nodule
– Age<20 & >70
– Presence of cervical lymphadenopathy.
– History of radiation to the neck
– - Family history of MTC, MEN2, or PTC

21. ULTRASONOGRAPHY FEATURES OF MALIGNANCY
• Hypoechogenicity in solid nodules,
• Presence of micro calcifications,
• Irregular shape,
• Taller than wider lesion
• Intra nodular vascular spots,
• Absence of halo and Cystic elements.
• Evidence of invasion or regional lymphadenopathy, and
• Increased blood flow in the center of the nodule
*Macroscopic Capsular Breach and Nodal involvement are diagnostic of malignancy.

22. U.S FEATURES OF BENIGN AND MALIGNANT NODULE

24. • Should be limited to patients with a low TSH level to identify autonomously
functioning nodules .
• Nodules with increased uptake (hot) are toxic adenomas and almost never
malignant. (1- 4% chances only).
• Nodules with low uptake (cold), are malignant in upto 25% of the cases and
therefore require FNA biopsy.
THYROID SCAN
(123 IODINE OR 99 M TECHNETIUM)

25. CT SCAN / MRI
• CT Scanning & MRI role is limited, except to see the spread and compression of
neighboring structures.
• Both can accurately determine substernal extension and invasion of
surrounding structures, such as esophagus, larynx, or trachea, and should be
used only if invasion or substernal extension is suspected.

26. PET- SCAN
• Indicated in follow up to detect recurrence.
• The phenomenon of the PET identified thyroid
incidentallomas is becoming more prevalent.

27. CONCLUSION
• The goal of the evaluation of the solitary thyroid nodule is to identify a malignancy.
• Common in females, 90% of them are benign, adenoma being the commonest amongst
benign lesion.
• FNAC is a very reliable and powerful screening method
• Jointly, FNAC, thyroid imaging, and ultrasonography can detect them with 90% accuracy.
• Thyroid scan is expesive .

28. Thank You