An autopsy case of malignant pleural mesothelioma presenting with an elevated G-CSF level and neutrophil-predominant pleural effusion.

A 77-year-old man was admitted with respiratory failure. Chest computed tomography revealed right pleural thickening and pleural effusion. A cytological examination of the pleural fluid showed a predominance of neutrophils without any malignant findings. The peripheral white blood cell count increased to a maximum of 74,070/μL. Laboratory tests revealed that the serum level of granulocyte colony-stimulating factor (G-CSF) was 268 pg/mL. The autopsy findings indicated malignant pleural mesothelioma. The clinical course was consistent with that of G-CSF-producing malignant pleural mesothelioma. This is a rare case of desmoplastic malignant pleural mesothelioma that clinically mimicked a G-CSF-producing tumor and empyema.