[Diagnostic yield of pancreatic percutaneous puncture depending on the size of the lesion].

INTRODUCTION The aim of the present study was to study the diagnostic efficacy of the percutaneous puncture of pancreatic tissue. MATERIAL AND METHODS A retrospective study was conducted on patients with suspicion of pancreatic neoplasm, and with a percutaneous biopsy of pancreatic tissue, from 2000 to 2011. For the statistical comparative analysis, the sample was stratified by tumour size: ≤ 3cm and > 3cm. RESULTS A total of 90 biopsies were performed. Pancreatic neoplasm diagnosis was made in 47 cases (52%), with 16 false negatives (18%), no false positives, and chronic pancreatitis in 24 cases (27%). The efficacy of the test results were: an overall sensitivity of 75% (95% CI: 62%-85%), a specificity of 100% (95% CI: 87%-100%), a positive predictive value of 100% (95% CI: 92%-100%), and a negative predictive value of 63% (95% CI: 46%-77%). For tumour sizes ≤ 3cm the sensitivity was 70% (95% CI: 45%-88%), with a specificity of 100% (95% CI 66%-100%), a positive predictive value of 100% (95% CI: 76%-100%, and a negative predictive value 60% (95% CI: 32%-83%). For tumours greater than 3cm, the sensitivity was 88% (95% CI: 70%-98%), the specificity was 100% (95% CI: 75%-100%), with a positive predictive value of 100% (95% CI: 85%-100%) and a negative predictive value of 81% (95% CI: 54%-96%). CONCLUSIONS Pancreatic percutaneous biopsy efficacy was strongly determined by lesion size. For tumour sizes less than 3cm, the sensitivity and negative predictive value are unacceptably low, as negative results would not reliable.