Production of granulocyte-macrophage colony-stimulating factor in a patient with metastatic chest wall large cell carcinoma

Recent reports of cancers that produce colony-stimulating factors (CSF) and which are associated with leukocytosis indicate that most are granulocyte CSF-producing tumors. A 71-year-old man with metastatic chest wall tumors from large cell lung cancer with marked leukocytosis and eosinophilia was reported. His maximal leukocyte count was 48300/microliter with 37.5% eosinophils. Granulocyte-macrophage CSF (GM-CSF) activity detected by enzyme-linked immunosorbent assay (ELISA) in serum was 112 pg/ml (normal range < 2.0 pg/ml), but G-CSF was normal. Immunohistochemical detection of GM-CSF protein on a chest wall tumor sample was positive. Irradiation of the chest wall tumor was performed and the leukocyte count decreased temporally. However, he died of respiratory failure due to progressive tumor growth 56 days after admission. Based on these results it appears that autocrine production of GM-CSF is a possible cause of this leukemoid reaction.