Endoscopic Retrograde Cholangiopancreatography (ERCP) Brush-Based Cytology Vs Biopsy: a Comparative Diagnostic Study

Endoscopic retrograde cholangio-pancreatography (ERCP) brush-based cytology is a valuable diagnostic tool regarding the biliary system examination and detection of non- or malignant lesions. Diagnostic accuracy and sensitivity of this method demonstrate different ranges in a variety of studies. The aim of the current study was to compare the results of ERCP brush-based cytology with the corresponding histopathological diagnoses.

We selected and compared cytological and pathological slides derived from sixty-eight (n=68) patients who underwent ERCP brush-based examination between February 2021 and March 2024. Papanicolaou and eosin-hematoxylin staining assays were performed in the corresponding smears and tissues, respectively.

Concerning the initial cytological diagnoses, 38 cases were negative for malignancy, 10 cases atypical, 16 cases suspicious for malignancy and four cases were characterized as positive for malignancy. Histologic correlation confirmed a benign outcome in 39 out of 48 patients, 11 cases were diagnosed as adenoma-dysplasia, whereas 18 cases were considered malignant. The overall concordance between cytology and histology was 66% in sensitivity, 95% in specificity, 84% in accuracy, 90% in positive predictive value and 81% in negative predictive value.

Endoscopic retrograde cholangio-pancreatography brush-based cytology is a useful and significant preoperative method for initially diagnosing pancreatic-biliary lesions. It provides a high level of specificity, accuracy and predictive value (positive/negative), but a lower level of sensitivity compared to histopathology due to differences that cell and tissue substrates demonstrate during the diagnostic process (morphological features and cell configuration/cyto-architecture).