Abstract
A 42-year-old man went to a pulmonary clinic for a fever of 2 months' duration. The results of a complete blood count showed an increase in leukocytes to more than 20,000/mm3. A CT scan of the chest showed a mass measuring 6 cm in diameter contiguous with the mediastinal pleura. Because pulmonary abscess was suspected, the patient was treated with antibiotics for a month, but no improvement was noted. He was referred to our hospital for further examination and therapy. Elevations of both serum granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) were shown on laboratory examination. Upper lobectomy of the right lung was performed. Poorly differentiated adenocarcinoma of the lung was subsequently diagnosed. An immunohistochemical study with anti-G-CSF monoclonal antibodies revealed G-CSF protein in the tumor cells. After removal of the tumor, the leukocyte count, serum G-CSF level, and serum IL-6 level normalized. As G-CSF-producing lung cancer generally has a poor prognosis, close follow-up is essential.
