Single Centre Retrospective Study on Intraductal Papillary Neoplasm of the Bile Duct Incidence: Are We Reporting All Cases?

Purpose: Intraductal papillary neoplasm of the bile duct (IPNB) is considered a premalignant condition, with an increasing number of cases identified and reported. Early stage’s diagnosis is challenging and surgery is recommended. We analyse its incidence in our centre. Methods: From January 2014 to January 2021 five cases were identified from the pathology reports. Demographic characteristics, perioperative assessment and management, histology analysis and follow-up were retrospectively analyzed. The present study fulfils the institution´s ethics committee requirements. Results: Preoperative assessment included abdominal ultrasound, multiphasic contrast enhanced CT and MRCP in all cases, identifying three cases as IPNB. Left lateral sectionectomy was performed in one case, right hepatectomy in two cases and left hepatectomy in two cases. One case required reoperation due to bleeding and the other patients had an uneventful recovery. The pathology reports revealed a mean tumour size of 2.9 cm, with low-grade dysplasia in one case, moderate in two and high-grade in one case. Lymph node disease (N1) was present in one case. All in all, tumours were regarded as pTis in four cases and pT1b in one case. All cases were R0. Immunohistochemistry was available in 3 cases, CK7 was positive in all cases and MUC5 in two. One patient received adjuvant Capecitabine and one case presented a second tumour six years after the initial diagnosis, undergoing redo liver resection (pT1aN0 M0, R0, G2 cholangiocarcinoma). Follow-up ranged from 6-84 months, one patient was lost to follow-up after six months. Follow-up scheme was annual or biannual with US/CT or MR plus outpatient clinic review. Conclusion: IPNB is a relatively new condition and accordingly our reduced series showed significant heterogeneity, in terms of presentation and final histology reports too. We recommend that radiological and pathological reports as well as follow up, should be standardised in order to facilitate recognizing this entity, which might be underdiagnosed. Creating an international registry could contribute to achieve that goal.EP257_Table 1Clinicopathological data of the included patients.AgeSexPMHCA 19.9BilirubinSymptomsPreoperative diagnosis of IPNBLocationSurgeryTNM74MPBCnormal↑Abdominal painyesintrahepaticRight HpTisN069FBreast canormalnormalIncidental findingnointrahepaticII-IIIpTisNx66FColon ca↑normalIncidental findingyesintrahepaticLeft HpT1bNx77MBladder canormal↑Abdominal painnointrahepaticLeft HpTisN154FOvarian canormalnormalAbdominal painyesintrahepaticRight HpTisN0PMH: previous medical history, ca:cancer, H: hepatectomy Open table in a new tab PMH: previous medical history, ca:cancer, H: hepatectomy