Characteristics of bile duct carcinoma with superficial extension in the epithelium

Longitudinal tumor extension from the main tumor involves intramural or superficial spread along the bile duct, which influences surgical curability. Identifying the range of superficial extension is difficult by preoperative imaging. To clarify specific characteristics of bile duct carcinoma (BDC) with superficial extension of epithelium in the bile duct, we examined clinicopathologic features and patient outcomes in BDC patients with or without superficial extension who underwent surgical resection.

Between 1994 and 2008, we retrospectively examined clinicopathologic findings and outcomes for 42 BDC patients who underwent surgical resection and divided them into two groups: (1) superficial extension (SE) group (n = 10); and (2) non-SE group (n = 32).

In terms of macroscopic growth of the main tumor, the papillary type was more common in the SE group than in the non-SE group, whereas the nodular type was dominant in the non-SE group. The prevalence of cancer-positive findings at the cut end of the bile duct was higher in the SE group. Portal vein invasion was not observed in the SE group, and the prevalence of regional lymph node metastasis was significantly greater in the non-SE group than in the SE group. No patients died of cancer in the SE group, who tended to show better survival than the non-SE group.

The present results suggest that a good prognosis may be achieved in BDC patients with SE when complete resection is accomplished.