Fig 1.
Criteria for the morphologic classification of IPNB.
The IPNBs were morphologically classified into three types: branched, main duct, and mixed types, based on the specific criteria. (A) This criteria combine two independent factors: cystic and bile duct characteristics, which are assessed through preoperative imaging studies. (B) The representative schemas for each morphologic type. Abbreviations: IPNB, intraductal papillary neoplasm of the bile duct.
Table 1.
Patient demographics according to morphologic classification.
Fig 2.
Postoperative survival by morphology and lesion extent in all IPNB cases.
DSS in patients with IPNB was compared according to (A) morphological subtype—branched, main duct, and mixed—and (B) anatomical extent of the tumor—confined to the intrahepatic bile duct, extrahepatic bile duct, or both. No disease-specific deaths occurred in the branched type. There was no significant difference in DSS between the branched and main duct types. In contrast, the mixed type showed significantly worse 1-, 3-, and 5-year DSS compared to the branched type (p = 0.044). DSS did not significantly differ among the groups based on tumor extent. Abbreviations: DSS, disease-specific survival; IPNB, intraductal papillary neoplasm of the bile duct.
Fig 3.
Postoperative survival by pathological tumor progression factors in IPNB with associated invasive carcinoma.
In patients with invasive IPNB, DSS was analyzed according to pathological indicators of tumor progression: (A) invasion depth, (B) lymph node metastasis, and (C) residual tumor status. Patients with tumor invasion beyond the bile duct wall (SE or SI) had a 5-year DSS rate of 0%, significantly lower than those with M or FM invasion (p < 0.001). The presence of lymph node metastasis was also associated with significantly worse 5-year DSS (p = 0.021). Patients with residual tumor (R1 or R2) had lower 5-year DSS than those with curative (R0) resection, although this difference did not reach statistical significance (p = 0.119). Abbreviations: DSS, disease-specific survival; IPNB, intraductal papillary neoplasm of the bile duct Tumor depth: M (mucosal)/ FM (fibromuscular)/ SS (subserosa)/ SE (serosal exposure)/ SI (serosal invasion).
Fig 4.
Postoperative recurrence by morphology in IPNB with associated invasive carcinoma.
The association between postoperative recurrence and morphological subtypes was evaluated in patients with invasive IPNB. No recurrence was observed in the branched type. In contrast, the mixed type showed a high 5-year recurrence rate of 62%. The main duct type had an intermediate risk, with a 5-year cumulative recurrence rate of 13%. Abbreviations: IPNB, intraductal papillary neoplasm of the bile duct.