A retrospective study on the comparative use of fine-needle biopsy and aspiration for the diagnosis and classification of malignant lymphoma in Japan.

Abstract

Background/aims: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is essential for diagnosing malignant lymphoma (ML). However, the optimal needle type for maximizing the diagnostic yield and tissue quality remains unclear. We compared the diagnostic performance and histological tissue quality between fine-needle biopsy (FNB) and fine-needle aspiration (FNA) needles in EUS-TA for ML.

Methods: This retrospective study included patients who underwent EUS-TA for suspected ML. The diagnostic accuracy, histological sample quality assessed by scoring, and adverse events were compared between the FNB and FNA groups. A subgroup analysis was performed for 22-gauge needles.

Results: FNB demonstrated higher diagnostic accuracy (75%) than FNA (50%) for cytology, with 100% sensitivity for histological diagnosis compared with 78.9% for FNA. The FNB group had significantly higher diagnostic rates for the World Health Organization subclassification of ML (71.4% vs. 31.6%, p=0.037). Additionally, FNB obtained superior histological quality, with 71.4% of samples scoring 5 compared with 41.2% in the FNA group. Adverse events were minimal in both groups.

Conclusions: EUS-FNB showed better diagnostic performance and histological tissue quality than EUS-FNA for ML, particularly in obtaining adequate samples for histological evaluation and subclassification. Therefore, EUS-FNB can be safely performed. Future research with larger sample sizes and genetic testing is warranted.