Core needle biopsy in patients with suspected lymphoproliferative disease: diagnostic yield in a large single-center cohort and procedural techniques

Abstract Purpose Excisional biopsy is considered the gold standard for lymphoma diagnosis, but is invasive and not always feasible. Imaging-guided core needle biopsy (CNB) has emerged as a minimally invasive alternative; however, no consensus exists regarding its use as a first-line diagnostic tool in suspected lymphoproliferative disease. Objective of this study was to evaluate the diagnostic yield of CNB in an intent-to-diagnose cohort of patients referred with suspected lymphoproliferative disease. Methods We retrospectively reviewed 1059 adult and pediatric patients with suspected lymphoproliferative disease referred to Fondazione IRCCS Istituto Nazionale dei Tumori in Milano between 2010 and 2022. The primary outcome was first-procedure CNB diagnostic yield in the whole suspected cohort, defined as the proportion of CNBs providing a conclusive histological diagnosis without requiring subsequent surgical biopsy. A secondary analysis focused on patients with a final diagnosis of lymphoma. Data on biopsy site, imaging guidance, PET-CT availability within 30 days before biopsy, needle gauge, number of samples, diagnostic yield, and complications were collected. Results A conclusive CNB diagnosis was obtained in 1023 of 1059 patients referred with suspected lymphoproliferative disease (96.6%; 95% CI, 95.3–97.5). A final diagnosis of lymphoma was made in 882 patients (85%), whereas 177 patients (15%) had non-hematological conditions diagnosed by CNB. Twenty-two patients were pediatric. In the lymphoma cohort, 846 of 882 CNBs were diagnostic without the need for additional procedures (95.9%; 95% CI, 94.4–97.0), while 36 patients (4.1%) required subsequent excisional biopsy. Diagnostic yield was similar for US-guided (95.8%; 95% CI, 94.1–97.0) and CT-guided biopsies (97.1%; 95% CI, 91.9–99.0). No complications > = grade 2 according to CTCAE v5 were observed. Conclusions In a large single-center cohort, imaging-guided CNB provided a conclusive diagnosis in 96.6% of patients referred with suspected lymphoproliferative disease and in 95.9% of those ultimately diagnosed with lymphoma. These findings support CNB as a safe and effective first-line diagnostic approach, while emphasizing that prompt excisional biopsy remains necessary when CNB is not evaluable or is suggestive but not conclusive.