# The Importance of the Interventional Pathologist in Fine Needle Aspiration and Core Needle Biopsy Procedures for Lymph Node Lesions: A Retrospective Analysis of Diagnostic Correlation and Proposal of a Classification System for Lymph Node Core Needle Biopsies

## TL;DR

This study shows how pathologists using FNA and CNB can accurately diagnose lymph node lesions, suggesting a new classification system for better communication.

## Contribution

The paper proposes a classification system for CNB in lymph node lesions and highlights the role of interventional pathologists in improving diagnostic accuracy.

## Key findings

- FNA had a 98% diagnostic yield with 94% correlation to CNB results.
- Ultrasound guidance improved lesion characterization in FNA procedures.
- A new classification system for CNB is proposed to align with the Sydney system for FNA.

## Abstract

Introduction: Pathology requires the integration of macroscopic and microscopic findings for an accurate diagnosis. Fine needle aspiration biopsy (FNA) traditionally became the domain of radiologists with the introduction of ultrasound; however, its increased accessibility has allowed other specialists, including pathologists, to incorporate it into their daily practice. Both ultrasound-guided FNA and core needle biopsy (CNB) performed by interventional pathologists have proven valuable tools in the diagnosis of lymph node lesions. Materials and Methods: An observational, descriptive, retrospective study was conducted at Hospital Universitario del Henares, analysing 134 FNABs and 31 CNBs of lymph node lesions between 2023 and 2024. The diagnostic yield of both techniques and their correlation were evaluated. Results: Ultrasound facilitated better lesion characterization. FNA demonstrated a diagnostic yield of 98%, with a 94% correlation with CNB results. The Sydney system 2020 was applied to FNA reporting in lymphatic node. An equivalent classification system for CNB is proposed. Conclusion: The performance of FNA and CNB by pathologists optimizes diagnosis, reduces time and costs, and strengthens their role in minimally invasive diagnostics. Adoption of a unified classification system for CNB lesions would facilitate communication between specialists.