Effectiveness of endoscopic ultrasound-guided tissue acquisition with stereomicroscopic on-site evaluation for preoperative diagnosis of resectable or borderline resectable pancreatic cancer: a prospective study.

Background/aims: To validate endoscopic ultrasound-guided tissue acquisition (EUS-TA) used in conjunction with stereomicroscopic on-site evaluation (SOSE) as a preoperative diagnostic tool for resectable pancreatic cancer (R-PC) and borderline resectable PC (BR-PC).

Methods: Seventy-eight consecutive patients who underwent EUS-TA for suspected R-PC or BR-PC were enrolled. The primary endpoint was the sensitivity of EUS-TA together with SOSE based on the stereomicroscopically visible white core (SVWC) cutoff value. One or two sites were punctured by using a 22-gauge biopsy needle for EUS-TA, based on the SOSE findings.

Results: We collected 99 specimens from 56 and 22 patients with R-PC and BR-PC, respectively. Based on the SOSE results, we performed 57 procedures with one puncture. The SVWC cutoff values were met in 73.7% and 73.1% of all specimens and in those obtained during the first puncture, respectively. The final diagnoses were malignant and benign tumors in 76 and two patients, respectively. The overall sensitivity, specificity, and accuracy of EUS-TA for the 78 lesions were 90.8%, 100%, and 91.0%, respectively. The sensitivity for malignant diagnosis based on the SVWC cutoff value were 89.5% and 90.4% for the first puncture and all specimens, respectively.

Conclusions: The sensitivity of EUS-TA in conjunction with SOSE for malignancy diagnosis in patients with suspected R-PC or BR-PC was 90.4%.