A Laparoscopically Treated Case of Peritoneal Dissemination Mimicking Liver Metastases from Distal Cholangiocarcinoma Four Years After the Initial Pancreaticoduodenectomy.

BACKGROUND/AIM:Operable peritoneal dissemination from distal cholangiocarcinoma after pancreaticoduodenectomy is rare. Furthermore, peritoneal dissemination mimicking liver metastasis has scarcely been reported. CASE REPORT:An 81-year-old woman received pancreaticoduodenectomy for distal cholangiocarcinoma. She was diagnosed with stage IIA (T3a N0 M0) and received curative resection. She did not receive adjuvant chemotherapy. As a result of the examination in our department, she showed two tumors, 20 mm and 8 mm in segments 7/8 and 7, respectively, in the subphrenic liver surface four and half years after the initial pancreaticoduo-denectomy. The larger tumor was slow-growing, and cystic degeneration was inside. Plain computed tomography imaging revealed an isodense tumor with a marginal high ring and weak early enhancement, and prolonged peripheral enhancement was recognized at the marginal portion. Magnetic resonance imaging showed a heterogeneous mass with peripheral hypointensity ring that may be caused by fibrous tissue. Although the smaller tumor was diagnosed only after admission, it presented similar imaging findings to the larger tumor. The preoperative diagnosis was suspected to be liver metastases from DCC or inflammatory pseudotumor. Laparoscopic partial liver resection with diaphragm dissection was performed for both tumors. Pathologically, the tumors were diagnosed as peritoneal dissemination from distal cholangiocarcinoma. In the disseminated cancer cells, the expression of Ki67 was decreased, which was suspected to be one of the reasons for the long recurrence-free interval. The patient is doing well without any recurrence three months after the second operation. CONCLUSION:Laparoscopic surgery can provide excellent results for diagnosing and treating unknown subphrenic tumors.