A Case of Granulocyte Colony-Stimulating Factor (G-CSF)-Producing Lung Cancer Proved by Immunohistochemical Analysis

症例は59歳, 男性で全身倦怠感および咳嗽を主訴として来院した.胸部X線写真では左下肺野に浸潤影を伴う腫瘤影を認めた.検査成績では, 明らかな感染症がないにもかかわらず32, 000/μlと著明な白血球増多がみられた.血清中のG-CSF値は酵素標識免疫法で298pg/mlと高値を示していた。臨床的に病期IIIAの肺扁平上皮癌と診断し, 左肺全剔術を施行した.手術時に得られた腫傷組織の抽出液および腫傷細胞の組織培養上清のG-CSF濃度は高値であった.rhG-CSFに対する特異的モノクローナル抗体を用いた免疫染色法では手術標本の腫傷細胞は陽性に染まった.術後, 白血球数および血清中のG-CSF値はすみやかに正常化した.現在, 術後2年経過しているが, 再発もなく健在である.A 59-year-old man was admitted to our hospital because of general malaise and cough. The chest X-ray film disclosed a mass shadow with infiltration in the left lower lung field. The laboratory data showed marked leukocytosis (32, 000/μl) without any evidence of infection. The serum level of G-CSF (298pg/ml) was high by enzyme immunoassay. A clinical diagnosis of lung cancer (squamous cell carcinoma, stage IIIA) was made and left pneumonectomy was performed. The level of G-CSF was high not only in the extract of tumor tissue obtained at operation but also in the supernatants of cultured tumor cells. An immunoperoxidase staining method using specific monoclonal antibodies against rhG-CSF showed positive staining in the tumor cells of the surgical specimen. After the operation, white blood cell counts and the level of serum G-CSF soon returned to normal. The patient has been in good health for two years after surgery without any evidence of recurrence