Published online Jan 21, 2020. doi: 10.3748/wjg.v26.i3.366
Peer-review started: October 13, 2019
First decision: December 5, 2019
Revised: December 13, 2019
Accepted: December 22, 2019
Article in press: December 22, 2019
Published online: January 21, 2020
Despite an expanding number of studies on intraductal papillary neoplasm of the bile duct (IPNB), distant metastasis remains unexplained especially in cases of carcinoma in situ. In the present study, we report a rare and interesting case of IPNB without invasive components that later metastasized to lungs and brain.
A 69-year-old male was referred to our hospital due to suspected cholangiocarcinoma. Laboratory tests on admission reported a mild elevation of alkaline phosphatase, γ-glutamyl transpeptidase, and total bilirubin in serum. Endoscopic retrograde cholangiography revealed a filling defect in the common bile duct (CBD) extending to the left hepatic duct. Peroral cholangioscopy delineated a tumor in the CBD that had a papillary pattern. Multidetector computed tomography and magnetic resonance cholangiopancreatography detected partial blockage ot interlude in the CBD leading to cholestasis without evidence of metastasis. Therefore, a diagnosis of IPNB cT1N0M0 was established. Left hepatectomy with bile duct reconstruction was performed. Pathological examination confirmed an intraepithelial neoplasia pattern without an invasive component and an R0 resection achievement. The patient was monitored carefully by regular examinations. However, at 32 mo after the operation, a 26 mm tumor in the lungs and a 12 mm lesion in the brain were detected following a suspicious elevated CA 19-9 level. Video-assisted thoracoscopic surgery of left upper lobectomy and stereotactic radiotherapy are indicated. In addition to histopathological results, a genomic profiling analysis using whole exome sequencing subsequently confirmed lung metastasis originating from bile duct cancer.
This case highlights the important role of genomic profiling analysis using whole exome sequencing in identifying the origin of metastasis in patients with IPNB.
Core tip: An intraductal papillary neoplasm of the bile duct without an invasive component has unexpectedly metastasized to the brain and lungs. In addition to histopathological results, a genomic profiling analysis using whole exome sequencing subsequently confirmed lung metastasis originating from bile duct cancer by detecting 100 single nucleotide variants and 168 insertion/deletions.