Hepatocellular carcinoma producing granulocyte colony-stimulating factor: diagnosis and treatment

Granulocyte colony-stimulating factor (G-CSF) is a naturally occurring glycoprotein that is synthesized by stromal cells in bone marrow. Several cases of G-CSF-producing malignant tumors in various organs have been reported, but it is extremely rare in hepatocellular carcinoma (HCC). Here, we report a rare case of HCC producing G-CSF. The patient presented with a continuous fever and had a huge liver mass in the right lobe with portal vein tumor thrombus (PVTT) in the right first branch. He had marked granulocytosis, and his serum level of G-CSF was elevated. A complete curative liver resection was performed after preoperative radiotherapy to PVTT. The pathological findings of the resected specimen revealed poorly/moderately differentiated HCC, and immunohistochemical staining of G-CSF was negative the first time it was tested, but the second time, it was positive in the cytoplasm of other tumor cells of HCC. Only a few cases of G-CSF-producing HCC have been reported, and they resulted in rapid tumor growth, metastases, and poor prognosis. In our case with PVTT, there was no liver recurrence, although multiple lung metastases occurred at 8 months after curative resection. We should consider G-CSF-producing HCC and diagnose promptly when encountering liver tumor patients with leukocytosis, and we should perform multimodal treatment including radiation, radical surgery, and chemotherapy.