[A case of large cell carcinoma of the lung producing granulocyte colony-stimulating factor].

A 48-year-old female was admitted complaining of cough and right chest pain. A chest X-ray showed a tumorous mass in the right lower lung field and hilar and mediastinal lymphadenopathy. The patient underwent transbronchial lung biopsy, and was diagnosed as having a malignant tumor. Because a metastatic lesion was detected in the left lung filed, we opted for chemotherapy. The white blood cell count rose to 103,700/mm3 and 190,000/mm3 in the fifth and sixth month after hospitalization, respectively. The serum granulocyte colony-stimulating factor (G-CSF) level by enzyme immunoassay exceeded 1000 pg/ml. The histological diagnosis of large cell carcinoma was made from the specimen obtained by percutaneous needle biopsy of the lung. The carcinoma cells in this specimen, showed positive staining with anti-G-CSF monoclonal antibody.