FNAC of Lymph Nodes
Key Points
- Minimally invasive diagnostic procedure
- High sensitivity and specificity for lymphadenopathy
- Cost-effective first-line investigation
- Rapid diagnosis capability
- Can be performed in outpatient setting
Overview
Fine Needle Aspiration Cytology (FNAC) is a crucial diagnostic tool in the evaluation of lymphadenopathy in children. It involves the aspiration of cellular material from lymph nodes using a fine needle for cytological examination, providing valuable diagnostic information while being minimally invasive.
Clinical Indications
Primary Indications
- Persistent Lymphadenopathy
- Duration > 4-6 weeks
- Progressive enlargement
- Unexplained etiology
- Suspected Pathologies
- Infectious causes
- Tuberculosis
- Atypical mycobacterial infection
- Cat-scratch disease
- Malignancy screening
- Lymphoma
- Leukemia
- Metastatic disease
- Infectious causes
Pre-procedure Assessment
- Clinical History
- Duration of lymphadenopathy
- Associated symptoms
- Previous treatments
- Risk factors
- Physical Examination
- Size and location of nodes
- Consistency and mobility
- Presence of matting
- Associated findings
- Basic Investigations
- Complete blood count
- ESR/CRP
- Chest X-ray if indicated
- Ultrasonography findings
Procedure Details
Equipment Required
- Essential Items
- 22-25 gauge needles
- 10-20 ml syringes
- Glass slides
- Fixatives
- Sterile swabs
- Local anesthetic (if needed)
- Optional Equipment
- Syringe holder
- Ultrasound guidance
- Transport media for culture
Technique
- Preparation
- Explain procedure to child and parents
- Position patient appropriately
- Identify and mark the target node
- Clean the skin
- Aspiration Technique
- Fix node between fingers
- Insert needle with continuous suction
- Multiple passes in different directions
- Release suction before withdrawal
- Specimen Handling
- Rapid expulsion onto slides
- Proper smear preparation
- Air-dry and fix slides
- Label specimens correctly
Cytological Interpretation
Normal Findings
- Cellular Components
- Mixed lymphoid population
- Small mature lymphocytes
- Occasional histiocytes
- Plasma cells
Pathological Patterns
- Reactive Lymphadenitis
- Polymorphous lymphoid population
- Immunoblasts
- Tingible body macrophages
- Granulomatous Inflammation
- Epithelioid cells
- Giant cells
- Caseous necrosis in TB
- Malignant Features
- Lymphoma patterns
- Metastatic deposits
- Leukemic infiltration
Ancillary Studies
- Microbiological Studies
- AFB staining
- Culture and sensitivity
- PCR for tuberculosis
- Special Stains
- Immunocytochemistry
- Flow cytometry
- Molecular studies
Limitations & Follow-up
Procedure Limitations
- Technical Limitations
- Inadequate sampling
- Poor slide preparation
- Sampling error
- Deep-seated nodes
- Diagnostic Limitations
- Architecture not preserved
- Limited material for special studies
- Overlapping cytological features
Follow-up Requirements
- Immediate Follow-up
- Monitoring for complications
- Pain management if needed
- Care instructions
- Long-term Follow-up
- Review of results
- Additional investigations if needed
- Treatment planning
- Monitoring response
Potential Complications
- Minor
- Local pain
- Minor bleeding
- Bruising
- Rare Complications
- Infection
- Hematoma
- Nerve injury
