Malignant infiltrating intraductal papillary mucinous neoplasm with internal fistula: one case report and clinical practice.

BACKGROUND Intraductal papillary mucinous neoplasm (IPMN) is a rare tumor that originates in the pancreatic duct. The diagnosis of benign, borderline or malignant to IPMN is significant in terms of making an appropriate treatment plan and prognosis. This article summarizes our clinical experience of a case report and discussion by literature review. Methods and case report: A 73 year old male patient was admitted for an occupying lesion of the pancreas. The magnetic resonance cholangiopancreatography (MRCP) scan considered IPMN, endoscopic retrograde cholangiopancreatography (ERCP) also confirmed diagnosis of IPMN. Both the biliary and pancreatic duct stents were replaced, but we did not obtain any evidence by cytological evaluation. One month later, ERCP and intraductal ultrasonography (IDUS) showed infiltrating growth of the tumor. Endoscopic ultrasonography guided fine-needle aspiration was performed at the same time, and pathological diagnosis was suggested as borderline IPMN. RESULTS In the absence of pathological support, the patient presented with the clinical diagnosis of infiltrating intraductal papillary mucinous adenocarcinoma (IPMC) and was recommended for surgery. However, the patient and his family refused surgery, and were discharged. Subsequently, the patient died 6.5 months (197 days) following first diagnosis. CONCLUSIONS Currently, the definition and classification of IPMN is done by specification, although there remain some difficulties in diagnosing its subtypes. For diagnostic purposes, CT, MRCP, ERCP, IDUS, EUS and EUS-FNA can all be applied. Cytological negative pathology might not completely rule out malignancy, and would still require further examination and follow-up.