Neuroendocrine neoplasm of the cystic duct: report of two cases and literature review

Background: Neuroendocrine neoplasm (NEN) of the cystic duct (CD) is an extremely rare entity, with misty clinical manifestation and incidental, in most cases, diagnosis. Due to its rarity, several dilemmas arise concerning the optimal treatment of this type of malignancy.Case description: We report two cases of histologically confirmed NENs of the CD from our institution. Furthermore, we present a literature review focusing on the treatment type and likelihood of recurrence. The two patients underwent laparoscopic cholecystectomy (CCE) due to cholelithiasis and were both diagnosed with well-differentiated Grade 1 (G1) NEN. The first patient did not undergo further treatment as the surgical margins were clear. Regarding the second patient, complementary resection of the CD remnant was performed since the histopathological diagnosis indicated positive surgi-cal margins. Active postoperative surveillance was suggested, and both patients remain disease-free to date. In the literature, we identified 22 previous cases of NENs of CD. Since there are still no standard guidelines, various surgi-cal plans were adopted, varying from simple CCE to hepatic lobectomy and Roux en Y hepaticojejunostomy. Postopera-tive surveillance is reported for up to four years. Regardless of the implicated treatment plan, no patient was diagnosed with recurrent malignancy and the mortality rate was very low (1/22).Conclusion: We propose that cholecystectomy with ligation of the CD proximal to its junction with the common hepatic duct is an adequate oncological treatment for G1 NENs of the CD. When preoperative or perioperative suspicion for ma-lignancy is made, a frozen section of the CD should be sent for pathological examination to confirm radical resection (R0). Nevertheless, there is a need for further research that could validate our findings. HIPPOKRATIA 2021, 25 (3):141-144.