[Granulocyte colony-stimulating factor producing lung large cell carcinoma with sarcomatous transformation].

We report a case of granulocyte colony-stimulating factor (G-CSF) producing lung large cell carcinoma with sarcomatous transformation. A 57-year-old man was admitted for evaluation of an abnormal shadow near the right pulmonary hilus on chest X-ray film. Brush cytology specimen from right B6 disclosed large cell carcinoma. His clinical stage was already IIIB (T3N3M0) on admission, so we immediately administered chemotherapy and radiation therapy. However, the patient's condition gradually deteriorated and he died of respiratory failure. Although there was no evidence of infection throughout his clinical course, his peripheral white blood cell count gradually increased and reached 47,000/mm3 (neutrophils 96%) before death. Histological study of the autopsy specimen revealed that the primary tumor was composed of two different elements (large cell carcinoma and spindle cell sarcomatoid element). The spindle cell sarcomatoid element appeared to have arisen from sarcomatous transformation of carcinoma cells, because the transition margin of the carcinoma to the sarcomatoid element was smooth, and special and immunohistochemical staining of both elements showed the same properties. Moreover, immunohistochemical study with monoclonal antibody to human G-CSF, 4A6 clearly demonstrated granular staining of G-CSF in the cytoplasm of tumor cells.