Outcome Determining Factors of Intraductal Papillary Neoplasm of the Biliary Tract (IPNB)-a Single Center Survey and Analysis of Current Literature.

Purpose: Intraductal papillary neoplasms of the biliary tract (IPNB) are rare tumors originating from the bile duct epithelium. Metastatic disease of IPNB is extremely rare and only reported in a small number of cases worldwide. Due to this limitation in number, the treatment of IPNB mainly relies on retrospective case series.

Patients And Methods: We reported three cases of IPNB, one benign, one carcinoma with lymph node metastasis, and one case with histologically proven metachronous pulmonary metastasis. We correlated our findings with the existing data found in the literature. All patients underwent hemihepatectomy and complete tumor resection was achieved.

Results: Diagnosis of IPNB can be challenging due to varying presentation. The treatment of choice is surgical oncological resection in an early tumor stage. Long-term outcome highly depends on the underlying grade of dysplasia, multiplicity, and tumor-free margins. Aggressive tumor invasion is reported in up to 72% of cases in IPNB. Furthermore, the recurrence rate of IPNB is high with up to 22%. Further factors associated with an impaired survival are incomplete resection, lymph node involvement, and MUC1 expression.

Conclusion: High potential for dysplasia and proof of invasive carcinoma upon diagnosis are hallmarks of IPNB. Metastatic disease in IPNB is reported only in small numbers. IPNB is an aggressive tumor entity with impaired long-term outcomes. A drawback for interpretation of current data is the fact that they rely on case series and reports and are not validated through more powerful randomized multicentric trials.