Touch imprint cytology on endoscopic ultrasound fine‐needle biopsy provides comparable sample quality and diagnostic yield to standard endoscopic ultrasound fine‐needle aspiration specimens in the evaluation of solid pancreatic lesions

Objectives Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is the gold standard for the diagnosis of solid pancreatic lesions (SPLs). Cytological samples can also be obtained using touch imprint cytology (TIC) on EUS fine‐needle biopsy (FNB) specimens. We aimed to compare sample quality and diagnostic yield of EUS‐FNA‐standard cytology (EUS‐FNA‐SC) to that of EUS‐FNB‐TIC in a series of patients with SPLs. Methods Thirty‐two consecutive patients referred for EUS‐tissue acquisition of SPLs who underwent rapid on‐site evaluation of both EUS‐FNA‐SC and paired EUS‐FNB‐TIC during the same endoscopic session were retrospectively identified. Sample quality (evaluated in terms of blood contamination, presence of clots, tissue casts, cellularity, and necrosis) and diagnostic yield were compared between the techniques. Results The mean number of passes to reach diagnosis at rapid on‐site evaluation was similar between EUS‐FNA‐SC and EUS‐FNB‐TIC (1.09 ± 0.3 vs 1.13 ± 0.34, P = .711). EUS‐FNA‐SC scores of sample quality were comparable to those of EUS‐FNB‐TIC (blood contamination, 2.47 ± 1.11 vs 2.25 ± 1.14, P = .109; clots, 1.25 ± 0.76 vs 1.19 ± 0.69, P = .624; tissue casts, 3.56 ± 0.88 vs 3.59 ± 1.09, P = .872; cellularity, 2.84 ± 1.11 vs 3.09 ± 1.09, P = .244; necrosis, 2.25 ± 1.08 vs 2.53 ± 1.02 P = .059; total score, 12.38 ± 2.88 vs 17.66 ± 2.38, P = .536). Adequacy, sensitivity and diagnostic accuracy of the two sampling techniques were equal (93.7%, 90.6% and 90.6%, respectively). Conclusions EUS‐FNB‐TIC provides comparable samples to those of EUS‐FNA‐SC and combines the benefits of cytology and histology for the evaluation of SPLs by employing a single needle during the same endoscopic procedure. Cytology and histology present pros and cons in the preoperative evaluation of solid pancreatic lesions, and which one should be preferred is still a matter of debate. The use of the touch imprint cytology on EUS‐fine‐needle‐biopsy specimens allows to combine the benefits by providing cytological and histological samples acquired during the same procedure and with the same needle. In our study sample quality and diagnostic yield of EUS standard cytology and EUS touch imprint cytology were evaluated in patients who underwent EUS‐FNA and paired EUS‐FNB with rapid‐on‐site assessment of the same lesion.