A case of granulocyte colony-stimulating factor producing lung adenocarcinoma with anaplastic lymphoma kinase gene rearrangements

A 49-year-old woman was diagnosed with lung adenocarcinoma, stage IIIB, with increased leukocytes and neutrophils. Positron emission tomography showed dense uptake in right lung, but not in the bone marrow or bone. Biopsy revealed positive anaplastic lymphoma kinase (ALK) gene rearrangements. First-line ALK inhibitor, crizotinib, was used for 9 weeks and its effect was limited. Second-line ALK inhibitor did not show effect. Positive immunostaining and high serum granulocyte colony-stimulating factor (G-CSF) levels confirmed G-CSF-producing lung adenocarcinoma. The patient died after 4.5 months of diagnosis. This is the first reported case of G-CSF-producing lung cancer with ALK rearrangements.