Common Bile Duct Diameter in Bladder Urothelial Carcinoma: A Case-Control Study

Although sporadic case reports have suggested an association between bladder urothelial carcinoma and common bile duct (CBD) dilation, no comprehensive study has investigated this association. This study aimed to compare CBD size in patients with urothelial carcinoma and matched controls.

In this retrospective case-control study, we analyzed 63 patients diagnosed with urothelial carcinoma alongside a control group of 63 individuals who were matched for age, gender distribution, smoking habits, and opium use. Demographic and clinical data were extracted from patient records. An experienced radiologist who was blinded to the study objectives measured the diameter of the CBD using CT scans.

The mean CBD diameter was larger in patients with urothelial carcinoma compared with the control group (6.81±2.77 vs 5.40±1.43, p = 0.004). Furthermore, individuals with tumor recurrence (8.58±3.45 vs 6.15±2.17, p = 0.005) or metastases (8.35±4.16 vs 6.52±2.38, p = 0.049) exhibited significantly higher CBD diameters compared with those without. However, regression analysis identified tumor recurrence (OR=7.63 [1.64-35.60]) and abnormal CRP (OR=9.85 [1.46-66.62]) as the only significant risk factors for abnormal CBD diameter.

Patients with urothelial carcinoma demonstrated larger CBD diameters than matched controls, with greater dilation observed among those with tumor recurrence. These findings suggest a potential association between urothelial carcinoma and CBD diameter; however, given the observational design and limited sample size, the results should be considered exploratory and hypothesis-generating. Further large-scale prospective studies are required to validate these findings, clarify underlying mechanisms, and determine their clinical significance.