Which specialist performs fine-needle aspiration cytology (FNAC) of an inguinal lymph node?

Specialist Who Performs Fine-Needle Aspiration Cytology of Inguinal Lymph Nodes

Fine-needle aspiration cytology (FNAC) of inguinal lymph nodes is typically performed by interventional radiologists, particularly those with ultrasound expertise, as ultrasound guidance is the preferred method for this procedure. 1

Procedure Details and Specialists

• Ultrasound-guided FNAC is the recommended approach for sampling inguinal lymph nodes, especially in cases where dynamic sentinel node biopsy (DSNB) is not available 1
• The procedure is commonly performed by:
  • Interventional radiologists with ultrasound expertise 1
  • Cytopathologists trained in aspiration techniques 2
  • Surgeons with specific training in FNAC techniques 1

Clinical Indications

• FNAC is indicated for:
  • Palpable inguinal lymph nodes to diagnose potential metastases 1
  • Non-palpable but suspicious nodes visualized on imaging 1
  • Follow-up of patients with known malignancies that may metastasize to inguinal nodes 3, 4

Diagnostic Value

• FNAC has high diagnostic accuracy when performed properly:
  • Sensitivity of 76.9-91.7% 2, 4
  • Specificity of 98.2-100% 2, 4
  • Positive predictive value of 97.7% 2
  • Negative predictive value of 95.45% 2

Procedural Considerations

• The conventional aspiration method is used with on-site cytologic examination 2
• Multiple preparation methods enhance diagnostic accuracy:
  • Papanicolaou-stained fixed smears
  • Diff-Quik-stained air-dried smears
  • Cell block preparation for histologic architecture assessment 2, 5
• In cases of negative FNAC but clinically suspicious nodes, repeat biopsy or node excision is advised 1

Common Pitfalls to Avoid

• False-negative results may occur due to:
  • Sampling error (inadequate material) 5
  • Small metastatic deposits (<1 cm) 4, 5
  • Low-grade malignancies mimicking reactive lymphoid tissue 5
• False-positive results are rare but may occur with:
  • Viral-associated lymphadenopathy 5
  • Inflammatory conditions mimicking malignancy 5
• Up to 50% of palpable inguinal nodes at initial diagnosis may be enlarged due to inflammatory changes rather than metastatic disease 1

Clinical Pathway

• For non-palpable nodes in high-risk patients: ultrasound-guided FNAC is recommended when DSNB is not available 1
• For palpable nodes: direct FNAC is the preferred first-line diagnostic approach 1
• If FNAC is negative but clinical suspicion remains high, excisional biopsy should be considered 1
• Positive FNAC results can guide immediate management decisions, including the extent of surgical intervention 4