S3350 Growing Pains: Unusual Case of Cholangiocarcinoma in a Young Adult

Introduction: Cholangiocarcinoma is an aggressive malignancy that originates from the biliary epithelium, anywhere in the biliary tract from the intrahepatic biliary canaliculi to the terminus where the common bile duct enters the duodenum at the duodenal ampulla. This malignancy, which is 95% of the time adenocarcinoma, is often locally invasive or metastatic by the time it is detected. Usually predisposing factors include primary sclerosing cholangitis, parasitic infection of liver flukes, biliary tree calculi, cystic biliary lesions, chronic liver disease and genetic predisposition. Cholangiocarcinoma represents 3% of gastrointestinal malignancy and more common in men in ages 50-70 years. Case Description/Methods: Case of 24-year-old man with non-relevant past medical history, presents with episodic shortness of breath and low back pain that has been affecting daily life activities for the past 3 months. Symptoms are more notable on exertion. Patient first noted an intermittent, non-radiated low back pain after Crossfit training. Additional symptoms include, intermittent palpitations, constipation and unintentional 25 lbs weight loss during past month. Among imaging workup, chest computed tomography scan and Abdominal/Pelvic computed tomography scan were remarkable for right large pleural effusion and hepatomegaly with multiple hypodense lesions. Lumbar magnetic resonance imaging revealed L2 compression fracture and multiple lesions suggestive of malignancy. Positron emission tomography (PET) scan was also performed, which demonstrated disseminated nodules on hepatic, splenic, skeletal, and pulmonary regions. Clinical presentation and imaging studies are consistent with a malignancy with metastasis, without clear evidence of primary origin. Discussion: Patient initially presented with low back pain, significant weight loss and a PET scan suggestive of lymphoma with skeletal, pulmonary, nodal, hepatic & splenic involvement. However, upon performing right pleural fluid cytology, differential of lymphoma seemed less likely, and immunohistochemistry was suggestive of a pancreatobiliary neoplasia. Liver biopsy was performed to determine definitive diagnosis, which positive presence of a FGFR2 fusion was most consistent with an intrahepatic cholangiocarcinoma. Results were fundamental for identifying the primary tumor and indicating futibatinib as best choice of therapy as per genetic profile testing. Gene sequencing was key in providing targeted gene therapy as a precision medicine technique.