Leukemoid reaction is defined as leukocytosis exceeding 50,000 cells/mm(3). When it occurs in a patient with a malignancy, secondary causes such as infections, drugs, hematologic diseases and hemorrhage need to be ruled out. After excluding such causes, paraneoplastic leukemoid reaction can be considered as a diagnosis of exclusion. Paraneoplastic leukemoid reactions have been described in association with lung, gastrointestinal, genitourinary and head and neck cancers. However, pancreatic cancer with leukemoid reaction has been rarely reported. We diagnosed a case of a 55-year-old Korean woman with extreme leukocytosis associated with advanced pancreatic cancer.
Keywords: Leukemoid reaction; Pancreatic neoplasms; Paraneoplastic syndromes.