Intrahepatic cholangiocarcinoma producing granulocyte colony-stimulating factor and parathyroid hormone-related protein.

A 78-year-old man was referred to our hospital with suspected liver abscess. Fever and inflammatory reaction resolved after percutaneous drainage and administration of antibiotics. However, leukocyte count was remarkably increased, and hypercalcemia was noted. The liver mass was also enlarged, as observed in the follow-up abdominal CT scans. Therefore, a percutaneous needle biopsy was performed, and the histopathological findings indicated the presence of adenocarcinoma. Additional blood examination revealed high serum levels of granulocyte colony-stimulating factor (G-CSF) and parathyroid hormone-related protein (PTHrP). Lastly, the patient was diagnosed with cholangiocarcinoma producing G-CSF and PTHrP. Chemoradiotherapy with S-1 was initiated, which was partially effective. However, the patient died 134 days after initiating the therapy. Only two cases of cholangiocarcinoma producing G-CSF and PTHrP have been reported to date. Here we reported an additional case of cholangiocarcinoma producing G-CSF and PTHrP.