Context: The presentation of pancreatic cancer with a leukemoid reaction is rare with no prior reports in the English language literature.
Case report: We report a case of advanced pancreatic cancer presenting with leukemoid reaction. Granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor levels were normal while interleukin-6 was elevated. The patient had no evidence of infection. The leukemoid reaction correlated with tumor response.
Conclusion: This is the first case report in the English literature of a leukemoid paraneoplastic syndrome in a patient with pancreatic cancer. A clear correlation between tumor response, serum carbohydrate antigen 19-9 levels and leukemoid reaction is documented.