Intrahepatic Cholangiocarcinoma Masked as Fever of Unknown Origin Reza F. Saidi, M.D., Stephen G. ReMine, M.D., Michael J. Jacobs, M.D. Intrahepatic cholangiocarcinoma is a rare malignancy that often presents in an advanced stage. For many patients, early diagnosis is often delayed, secondary to vague symptoms and a lack of physical findings. Herein, we report an unusual case of fever of unknown origin secondary to intrahepatic cholangiocarcinoma. ( J GASTROINTEST SURG 2004;8:217–219)  2004 The Society for Surgery of the Alimentary Tract KEY WORDS: Fever, liver tumor, cholangiocarcinoma Cholangiocarcinoma is a rare tumor that most commonly involves the biliary confluence. An esti- mated 20% to 30% of cholangiocarcinomas originate in the extrahepatic bile duct, whereas less than 10% begin at the intrahepatic level. 1 Although cholangio- carcinoma is the second most common primary he- patic tumor after hepatocellular carcinoma, the intrahepatic variant accounts for less than 10% of malignant tumors of the liver. Furthermore, the intra- hepatic variant of this unusual cancer often remains asymptomatic until advanced stages. Herein we report a case of intrahepatic cholangiocarcinoma (IHC) that presented as a fever of unknown origin (FUO). CASE REPORT A 64-year-old white man presented for evaluation of a persistent fever that spanned 4 weeks. Medical history included an open aneurysmorrhaphy and graft placement for an infrarenal abdominal aortic aneu- rysm. The patient showed no signs of abdominal pain, pruritus, or jaundice. Furthermore, he denied having weight loss, change in bowel habits, or symptoms of peripheral ischemia. Physical examination revealed a diaphoretic, well-nourished male with an elevated temperature (100º F) and a well-healed laparotomy incision but was otherwise unremarkable. An exten- sive outpatient and in-patient diagnostic workup was Presented at the Fourth Americas Congress of the American Hepato-Pancreato-Biliary Association, Miami Beach, Florida, February 27–March 2, 2003. From the Department of Surgery, Providence Hospital and Medical Centers, Southfield, Michigan. Reprint requests: Michael Jacobs, M.D., Department of Surgery, Providence Hospital and Medical Centers, 22250 Providence Dr., Suite 700, Southfield, MI 48075. e-mail: mjjacobs@pol.net  2004 The Society for Surgery of the Alimentary Tract 1091-255X/04/$—see front matter Published by Elsevier Inc. doi:10.1016/j.gassur.2003.09.023 217 initiated and included routine laboratory assays, blood and urine cultures, and serial chest roentgeno- graphy. The serum hepatic transaminase and biliru- bin levels were normal; however, the alkaline phosphatase was slightly elevated. CT of the abdo- men demonstrated a large hypodense lesion within Couinaud segments II and III. Based on the suspi- cion that the lesion was an intrahepatic abscess, CT- guided transcutaneous aspiration was performed and a surgical consultation was subsequently ob- tained. Pathologic findings were consistent with ana- plastic carcinoma of unknown origin. A preoperative metastatic evaluation was performed and revealed a marginally elevated serum CA 19-9 level. The remainder of the workup was unremarkable and in- cluded CT of the thorax, bone scan, and upper/lower endoscopies. Because the patient was not jaundiced and did not demonstrate radiographic evidence of biliary obstruction, endoscopic retrograde cholangio- pancreatography and magnetic resonance cholangio- pancreatography were not performed. The patient underwent an exploratory laparotomy, left hepatec- tomy, and cholecystectomy without complications. The intraoperative findings included a large mass within Couinaud hepatic segments II and III, with intraoperative ultrasonography showing extension to segment IV. Tumor also extended into the falciform ligament, which was completely resected. Histopatho- logic examination revealed a 13 cm anaplastic IHC