Clinical and Imaging Features of a Focal Intrahepatic Biliary Stricture Visualized Only as Duct Dilatation.

Purpose: We assessed the proportion of patients with a focal intrahepatic stricture (FIHS) that was a precursor lesion or malignancy and visualized only as a duct dilatation.

Materials and methods: This retrospective study assessed patients who underwent surgery or biopsy for an FIHS on CT or MRI between January 2010 and March 2022. The number and proportion of non-precursor benign lesions, precursors, and malignancies were calculated. Clinical variables and imaging features were compared between non-premalignant benign and premalignant/malignant FIHSs.

Results: Twenty-eight patients with confirmed histopathological diagnoses were identified, including 15 men (54.0%) and 13 women (46.0%). The median age of all patients at the first imaging diagnosis was 65 ± 9.54 (range, 43-78) years. Of the 28 patients with FIHSs, 9 (32%) were diagnosed with cholangiocarcinoma and 7 (25%) were diagnosed with precursor lesions, which included six intraductal papillary neoplasms of the bile duct and one biliary intraepithelial neoplasm. Accordingly, 16 (57%) patients had malignant or precursor lesions, and 12 (43%) were diagnosed with non-precursor benign lesions. None of the clinical variables and imaging features used for analysis showed a statistically significant difference between the non-premalignant benign and premalignant/malignant FIHS groups (p > 0.05).

Conclusion: FIHSs visualized only as duct dilatation can harbor malignant or precursor lesions.