Differentiation of malignant and benign proximal bile duct strictures: the diagnostic dilemma.

Aim: To identify the criteria for the differentiation of hilar cholangiocarcinoma (HCCA) from benign strictures.

Methods: A total of 68 patients underwent resection of lesions suspicious for HCCA between 1998 and 2006. The results of laboratory investigations, imaging studies and brush cytology were collected. These findings were analyzed to obtain the final diagnosis.

Results: Histological examination of the resected specimens confirmed HCCA in 58 patients (85%, group I) whereas 10 patients (15%, group II) were diagnosed to have benign strictures. The most common presenting symptom was obstructive jaundice in 77% patients (79% group I vs 60% group II, P = 0.23). Laboratory findings showed greater elevation of transaminase levels in group I compared to group II. The various imaging modalities showed vascular involvement exclusively in the malignant group (36%, P < 0.05). Brush cytology was positive for malignant cells in only 50% patients in group I whereas none in group II showed malignant cells.

Conclusion: Despite improvements in imaging techniques, 10 patients (15%) with a presumptive diagnosis of HCCA were ultimately found to have benign strictures. Except for vascular involvement which was associated significantly with malignancy, there were no conclusive features of malignancy on regular imaging modalities. This uncertainty should be taken into account when patients with a suspicious lesion at the liver hilum are considered for resection.