Xanthogranulomatous appendicitis presenting asymptomatically 3 years after surgery for hilar cholangiocarcinoma: A case report.

INTRODUCTION:Xanthogranulomatous appendicitis (XGA) is a rare condition involving chronic inflammation of the appendix that is often difficult to distinguish from malignancy using imaging because of the formation of a heterogeneous mass with indistinct borders. Herein, we present a case of XGA with unusual clinical manifestations. PRESENTATION OF CASE:A 78-year-old female patient underwent radical resection of hilar cholangiocarcinoma with extended right hepatic lobectomy and biliary reconstruction. Three years postoperatively, she presented with an irregular mass in the right lateral pelvis, which was observed on computed tomography. The patient had not experienced recent clinical symptoms and did not present with abdominal tenderness. Routine blood tests did not indicate an increased inflammatory response; however, carcinoembryonic antigen levels continued to increase. Although disseminated recurrence of hilar cholangiocarcinoma and appendiceal carcinoma were suspected, XGA was diagnosed via laparoscopic appendectomy. DISCUSSION:XGA generally presents with symptoms of acute or chronic appendicitis, and is diagnosed incidentally during surgery. Hilar cholangiocarcinoma has a high recurrence rate, even after radical resection, and disseminated recurrence usually requires chemotherapy. In the present case, XGA was not suspected preoperatively because of the lack of physical symptoms and increased levels of tumor markers during follow-up for hilar cholangiocarcinoma. There have been no reports of XGA with such a confusing clinical course, thus confirming the difficulty in preoperatively diagnosing XGA. CONCLUSION:The preoperative diagnosis of XGA is difficult to differentiate from malignancy because of its clinical and imaging findings. We diagnosed the patient with XGA using laparoscopic surgery.