A combination of smears and cell block preparations provides high diagnostic accuracy for endobronchial ultrasound-guided transbronchial needle aspiration

Abstract

Endobronchial ultrasound-guided transbronchial needle aspiration has demonstrated its accuracy in the diagnostic workup of enlarged mediastinal lymph nodes. In addition to conventional smears, the use of liquid-based cytology (LBC) and cell block preparations (CBP) has been introduced more recently. The aim of our study was to determine the performance of each of the different techniques, separately and combined, in terms of diagnostic yield and sensitivity. A total of 290 consecutive patients were included. The pathological examination was based on smear cytology, LBC, and CBP. Adequate sampling was defined by the presence of pathological material or lymphocytes. The global diagnostic yield was 82.7 % and the sensitivity was 89.1 %. The diagnostic yield was 72.8 % for smears, 78.8 % for LBC, and 69.9 % for CBP. The combination of smears with CBP significantly increased diagnostic yield (p = 0.01) and sensitivity (p = 0.006), but not the combination of smears with LBC (yield: p = 0.07; sensitivity: p = 0.13). The combination of the three techniques further increased yield (p = 0.007) and sensitivity (p = 0.006), compared with smears alone. CBP were more sensitive than smears for both diagnoses of carcinoma (p = 0.01) and granulomatous inflammation (p = 0.048). Conversely, LBC was less sensitive than smears for granulomatous inflammation (p = 0.004), but the difference was not significant for carcinoma (p = 0.42). CBP, as a complement to smears, increases diagnostic yield and sensitivity for both diagnoses of carcinoma and granulomatous inflammation. LBC, if used alone, increases the risk of a false-negative result.

Comparison of multiple techniques for endobronchial ultrasound-transbronchial needle aspiration specimen preparation in a single institution experience

“…The diagnostic yield of slide cytology and core-tissue are reported to be greater than 80% also in previous series (4,(6)(7)(8). In our study no significant differences were seen between the diagnostic performances comparing these two techniques.…”

“…Also in the literature the combination of two techniques, both slide cytology and cell-block or core tissue, are reported to increase the diagnostic performance of the same methods alone (4,(6)(7)(8). However, processing the specimen in two different ways at the same time requires more resources and raises the question of which method should be trusted in case of discordant results.…”

Pre-analytical issues in effusion cytology

“…It is recommended that a cell block is prepared in conjunction with LBP (reports for TP) this is particularly important because fluids may contain large fragments that may not pass through the filter and are only noticed on the CB [15]. Other reports echoed similar findings in transbronchial aspirates and washes [16][17][18]. This has also been the first author's experience especially in hemorrhagic effusions.…”

The Implementation of Liquid-Based Cytology for Lung and Pleural-Based Diseases

“…Similarly, Wallas et al [12], in their study of aspirates processed by TP, reported 1 case of noncaseating granulomata detected only on CB. In the study by Gauchotte et al [14], the sensitivity for detecting granulomata was 30% for smears, 4.5% for TriP and 82.8% for CB (fig. 4).…”

“…3a). In endoscopic ultrasound-guided transbronchial needle aspiration, Gauchotte et al [14] reported a sensitivity of 86.4% for TriP and 92.9% for CP of SmCC. Using residual material from 101 Sp samples evaluated for SmCC, Wu et al [15] reported a diagnostic sensitivity of 80.2% for TriP versus 63.4% for smears.…”