Tissue Adequacy and Diagnostic Yield Assessment in Malignant Lymph Nodes Using Endobronchial Ultrasound (EBUS)-Guided Miniforcep Biopsy vs. EBUS-Guided Transbronchial Needle Aspiration

Abstract

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a predominantly used method for lymph node (LN) metastasis assessment. This study aims to identify tissue adequacy improvement with the addition of EBUS-guided miniforcep biopsy (EBUS-MFB) to EBUS-TBNA in sampling LNs.

Methods: We assessed tissue adequacy in patients with mediastinal and hilar lymphadenopathy, comparing the combination of EBUS-MFB and EBUS-TBNA with EBUS-TBNA alone. EBUS-MFB was performed with the guide sheath (GS) dilatation technique. Tissue adequacy was a tumor cell count (TCC) of >100 and neoplastic cell neoplastic cell estimate of >25%. Further, we reported the diagnostic yield, tumor cell characteristics, and safety outcomes.

Results: Among 69 patients (74 nodes), malignant diseases were diagnosed in 41 nodes using both techniques. Tissue adequacy with EBUS-TBNA (93.8% in 30/32 nodes) was comparable with the combined group (96.9% in 31/32 nodes, p=0.317). EBUS-TBNA yielded higher TCC (84.4% with >1,000 cells) than EBUS-MFB (53.1%, p=0.004). The combined approach significantly improved the diagnostic yield in non-malignant diseases compared with EBUS-TBNA alone (97% vs. 78.8%, p=0.014). Of the 32 nodes, 20 demonstrated discordant results between EBUS-TBNA and EBUS-MFB, with EBUS-MFB correctly diagnosing six nodes that EBUS-TBNA misdiagnosed. The complication rate was low (2.9%) with only minor bleeding reported.

Conclusion: EBUS-TBNA alone and the combination of EBUS-MFB and EBUS-TBNA demonstrated comparable tissue adequacy, with EBUS-TBNA exhibiting better specimen characteristics, potentially sufficient for various molecular analyses. The addition of EBUS-MFB, performed using the GS-dilatation technique, to EBUS-TBNA improved the diagnostic yield and proved to be a safe and efficient approach, particularly in non-malignant diseases.

Keywords: Endobronchial Ultrasound; Mediastinal and Hilar Lymphadenopathy; Miniforcep Biopsy; Tissue Adequacy; Transbronchial Needle Aspiration.

Fig. 1.

Endoscopic view of lymph node biopsy and endobronchial ultrasound procedure. (A) Image depicts the puncture site created by the transbronchial needle aspiration needle’s guide sheath. (B) Image illustrates the miniforcep, extended from the working channel, penetrating the bronchial wall and entering the right interlobar space. (C) Image presents the endobronchial ultrasound image of the right interlobar lymph node, with the opening of the miniforcep clearly visible within the lymph node. (D) Image displays the miniforcep being opened and slightly advanced for lymph node tissue biopsy.

Fig. 2.

Diagnostic flow diagram. *No lymphoid stroma and no specific diagnosis. EBUS: endobronchial ultrasound; TBNA: transbronchial needle aspiration; MFB: miniforcep biopsy; LN: lymph node.

Fig. 3.

Sampling node from discordant case between endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and EBUS-miniforcep biopsy (MFB). (A, B) Images illustrate samples from a patient with tuberculous lymphadenitis. The TBNA specimen in (A) presents entirely granular eosinophilic necrotic material without any granuloma (original magnification ×400). In contrast, the MFB specimen in (B) demonstrates an area of necrosis with a vague aggregate of epithelioid histiocyte, suggestive of granulomatous inflammation (original magnification ×400). (C, D) Image illustrate samples from patient with diffuse large B-cell lymphoma. In (C), the TBNA specimen shows small fragments of crushed lymphoid stroma (original magnification ×400), while (D), the MFB specimen, reveals diffuse, highly cellular infiltration of malignant small round cells, thereby confirming a lymphoma diagnosis with adequate tissue sample.