Paraneoplastic Hyperleukocytosis in Pancreatic Adenocarcinoma.

Background

Paraneoplastic hyperleukocytosis is a rare phenomenon observed in patients with adenocarcinomas and other malignancies. In this study, we present a case of paraneoplastic hyperleukocytosis in pancreatic adenocarcinoma secondary to excessive secretion of serum granulocyte colony-stimulating factor (G-CSF). Presentation: We report a 71-year-old Caucasian male who presented to our hospital with hyperleukocytosis in the setting of locally advanced pancreatic adenocarcinoma. The patient was recently diagnosed 4 months before presentation and received abraxane/gemcitabine in addition to palliative radiation therapy for continued gastrointestinal bleeding. During routine laboratory assessment, the patient was found to have a white blood cell (WBC) count of 153 K/UL (75% neutrophils and 14% bands). Bone marrow biopsy and cytology were negative for neoplastic features. Serum G-CSF levels returned markedly elevated, supporting the diagnosis of paraneoplastic hyperleukocytosis. Interestingly, the WBC count decreased significantly following each of two cycles of chemotherapy, further suggesting a paraneoplastic etiology of hyperleukocytosis. The patient did not receive any growth factor support at any point before or during treatment.

Conclusion

In conclusion, the presence of hyperleukocytosis in cancer should raise clinical suspicion of a paraneoplastic phenomenon when other possible causes have been excluded. Hyperleukocytosis in this setting may correlate with progression of disease and lessen with treatment.