An autopsy case of G-CSF producing pleomorphic carcinoma of the lung

Background : Pleomorphic lung carcinoma is rare. We report a case detected based on cytological findings. Case : A 56-year-old man admitted for walking and eating difficulty was found in chest X-ray and computed tomography (CT) to have a tumor 10 cm in diameter in the left upper lobe. Bronchial brushing cytology showed atypical cells with irregular nuclei against an inflammatory background. Most atypical cells were giant and multinuclear cells with bizarre nuclei and prominent nucleoli. Atypical cells with eccentric nuclei and clear cytoplasm were also seen. Emperipolesis was seen in a few giant cells. Poorly differentiated adenocarcinoma was suspected cytologically. Histologically, the tumor consisted of sarcomatoid giant cells, multinuclear cells, and spindle cells against an inflammatory background. The tumor also included a squamous cell carcinoma component. Immunohistochemically, sarcomatoid cells were positive for keratin, EMA, vimentin, and granulocyte-colony stimulating factor (G-CSF). The final diagnosis was pleomorphic carcinoma. Conclusions : Pleomorphic carcinoma is difficult to diagnose by cytology alone, but proliferation of cells such as multinuclear and spindle cells in cytological specimens should suggest the possibility of pleomorphic carcinoma.