P030 | ACCURACY OF ULTRASOUND-GUIDED CORE NEEDLE BIOPSY FOR THE EVALUATION OF LYMPHADENOPATHIES SUSPECTED OF LYMPHOMA. THE EXPERIENCE OF THE REGGIO EMILIA CENTER.

Introduction: Excisional biopsy has traditionally been considered the gold standard for lymphoma diagnosis, as recommended by the WHO and major clinical guidelines. However, it is often associated with patient discomfort, longer diagnostic timelines, and high healthcare costs. Reducing diagnostic burden is a key goal in hematological practice. Ultrasound-guided core needle biopsy (USCNB) is increasingly recognized as a reliable diagnostic alternative. This study aimed to evaluate the diagnostic accuracy of USCNB in patients with suspected lymphoma-related lymphadenopathy at the Diagnostic and Interventional Ultrasound Center in Reggio Emilia. Methods: We retrospectively reviewed pathology reports of all USCNBs performed for suspected lymphoma from August 2021 to January 2024. All procedures were conducted using 18-gauge automatic spring-loaded biopsy needles under ultrasound guidance. Histological, immunohistochemical, cytogenetic, and molecular analyses, essential for accurate diagnosis per WHO criteria, were performed on all samples. Diagnostic accuracy was defined as the proportion of conclusive diagnoses enabling appropriate therapeutic decisions (true positives + true negatives / total biopsies). Results: A total of 461 biopsies were analyzed from 405 patients (median age: 62 years). Lymph nodes were located in peripheral (laterocervical n=182, axillary n=100, inguinal n=86, supraclavicular n=33) and deep regions (abdominal n=55, thoracic n=5). The median lymph node diameter was 25 mm (range: 5–140 mm); the median number of needle passes was 6 (range: 2–14). The most frequent diagnoses included B-NHL (n=185), HL (n=42), and T-NHL (n=11). Sensitivity and specificity were 92.6% and 100%, respectively, with a false-negative rate of 4.1% (19 cases). Among these, lymphoma was subsequently confirmed via excisional biopsy (n=15), repeat USCNB (n=3), or transbronchial biopsy (n=1). Positive and negative predictive values were 100% and 90.8%, respectively. In 17 cases (3.7%), samples were non-evaluable. The overall diagnostic accuracy of USCNB was 92.2% (425/461), with similar accuracy for lymph nodes <20 mm (91.0%) and ≥20 mm (92.7%). Conclusions: Our findings support USCNB as a highly accurate and minimally invasive diagnostic tool for suspected lymphoma. It enables timely and effective treatment decisions while reducing the risks, costs, and delays associated with surgical biopsies.