Prospective pilot evaluation of a new needle prototype for endoscopic ultrasonography-guided fine-needle aspiration: comparison of cytology and histology yield.

Objectives Endoscopic ultralsonography (EUS) with the adjunct of EUS-guided fine needle aspiration has become an important diagnostic modality in gastroenterologic oncology. ELIS-guided fine needle aspiration mainly relies on cytology; data are scarce that compare cytology and histology. While testing a 22-gauge prototype needle, we prospectively compared the yield for both. Methods Forty-two consecutive patients (27 male, 15 female; mean age 59.2 years, range: 17-90 years) were included. In each patient we aimed to make two needle passes, and if the material acquired appeared insufficient macroscopically (no in-room cytopathology was available), further passes were done. The material was sent for cytological and histological assessment. Results A median number of two passes (range: 2-3) were uneventfully performed for pancreatic lesions (n=30), mediastinal and other lymph nodes/masses (n=8) and various other lesions (n=4) and yielded adequate material for cytology, histology or at least one of the two investigations in 62, 67 and 74% of patients, respectively. No false positive results were found (specificity 100%). Sensitivities were 58.6 and 65.5%, respectively, for cytology and histology alone; combined assessment increased sensitivity to 79.3%. When adjusted values were calculated, based only on those cases with adequate material, sensitivity was 89.5% for cytology and 85.7% for histology, and increased to 100% with combined assessment. Conclusion The new needle achieves sensitivities similar to those previously reported with no significant differences in sensitivity between cytology and histology. More effective tissue acquisition methods must be sought to improve overall results.