Endoscopic tissue diagnosis of cholangiocarcinoma

The extremely poor outcome in patients with cholangiocarcinoma, in large part, reflects the late presentation of these tumors and the challenging nature of establishing a tissue diagnosis. Establishing a diagnosis of cholangiocarcinoma requires obtaining evidence of malignancy from sampling of the epithelium of the biliary tract, which has proven to be challenging. Although endoscopic ultrasound-guided fine needle aspiration performs slightly better than endoscopic retrograde cholangiopancreatography in diagnosing cholangiocarcinoma, both endoscopic approaches demonstrate disappointing performance characteristics.

The limitations of cytologic analysis have recently led to the evaluation of new technologies such as digital image analysis and fluorescence in-situ hybridization to enhance diagnostic sensitivity. Both of these approaches carry the ability to identify malignant cells in samples of limited cellularity and thereby provide enhanced diagnostic sensitivity.

Overall, recognizing the limited sensitivity of diagnostic approaches for tissue diagnosis of cholangiocarcinoma, it would appear prudent to pursue further tissue sampling when there is a strong clinical suspicion of malignancy despite a prior negative/nondiagnostic result.