The document discusses the thyroid FNA procedure and diagnostic categories. It provides details on:
- Performing thyroid FNA under ultrasound guidance using a 25 gauge needle with 3-4 passes.
- Preparing direct smears, cytospins, cell blocks and liquid-based preparations from the aspirated material.
- The Bethesda system for reporting thyroid cytopathology which includes 6 diagnostic categories and their associated cancer risks to guide clinical management.
- Key cytologic features that help diagnose common thyroid lesions and cancers.
3. Fine Needle Non Aspiration (FNNA) biopsy
showing needle, position & direction for biopsy.
Immediately after FNA, firm pressure
is applied to biopsy sites
9. Thyroid FNA
The Cell Pattern Approach
• CELLS
– Arrangement
– Nuclear features
– Cytoplasmic features
• COLLOID
• BACKGROUND FEATURES
10. Clues to Diagnosis!
• More colloid
….more likely benign
• More cells
…. more likely neoplastic
11. The Bethesda System for Reporting Thyroid
Cytopathology: 6 Diagnostic Categories
• I. NONDIAGNOSTIC or UNSATISFACTORY
•
• II. BENIGN
• III. ATYPIA OF UNDETERMINED SIGNIFICANCE or FOLLICULAR
LESION OF UNDETERMINED SIGNIFICANCE
• IV. FOLLICULAR NEOPLASM or SUSPICIOUS FOR A FOLLICULAR
NEOPLASM
• - specify if Hürthle cell (oncocytic) type
• V. SUSPICIOUS FOR MALIGNANCY
• VI. MALIGNANT
•
12. TBRTC:
Relationship to Clinical Algorithms
Category Cancer Risk Management
Nondiagnostic or
Unsatisfactory
1-4% Repeat FNA with U/S
Benign <1-3 % Follow-up clinically
AUS, FLUS ~5-15 % Repeat FNA
Follicular Neoplasm, or
Suspicious for a Follicular
Neoplasm*
20-30 % Lobectomy
Suspicious for Malignancy
(usually papillary CA)
60-75 % Lobectomy or total
thyroidectomy
Malignant 97-99 % Total thyroidectomy
* Specify if HĂĽrthle cell type
13. Thyroid FNA: made Easy
• Granulomatous Thyroiditis
Giant cells munching on colloid
• Hashimoto’s Thyroiditis
Lymphocytes and oncocytes
• Papillary carcinoma
Papillae, nuclei and cytoplasm
• Medullary carcinoma
Carcinoid and amyloid
• Anaplastic carcinoma
Ugly giant and spindle cells
• Follicular lesions?
Colloid vs. follicular cells
17. VI: Malignant
Papillary thyroid carcinoma
• Papillae- not very
common
• Sheets: flat or
syncytial
• Sheets/ clusters
with well defined
borders
• Clusters: 3-D