Background: EUS-guided FNA (EUS-FNA) is an established tissue-acquisition technique, with most studies concentrating on cytologic analyses of specimens, with only few data existing on histologic assessment.
Objective: To assess the sensitivity of a combined analysis of histologic followed by cytologic tissue diagnosis.
Design: A retrospective 3-center study.
Methods: In consecutive patients undergoing FNA of solid pancreatic masses, core specimens were harvested for histology; residual tissue was examined cytologically. Only unequivocally positive results were regarded as malignant. Criterion standards were positive results from EUS-FNA or other histologic findings, or, if negative, clinical follow-up data (minimum 12 months).
Results: Among 192 patients (110 men; mean age 63 years) with mostly pancreatic-head masses (72.4%), overall, adequate tissue was obtained in 98.9% of all cases, with a mean of 1.88 needle passes and an overall sensitivity of 82.9% (95% CI, 76.0%-88.5%). Histology and subsequent cytology provided adequate tissue and sensitivities of 86.5% and 60%, and 92.7% and 68.1%, respectively. Excluding cases with inadequate specimens, sensitivities rose by 4% to 10%. Histology showed a trend for superiority over cytology only in characterizing nonadenocarcinoma tumor types. No differences in sensitivity were found between the centers involved.
Limitations: Retrospective design, different processing of cytologic specimens.
Conclusions: At EUS-FNA in pancreatic masses, combined histologic-cytologic analysis achieved a sensitivity of more than 80%, despite a low number of needle passes and may thus save time. Histology alone did not reach higher sensitivity than cytology. In particular situations, eg, rare tumors, histology may still be required.