Granulocyte Colony-stimulating Factor- and Interleukin-6-producing Large-cell Carcinoma of the Lung with Sarcomatoid Changes Suggestive of Epithelial-mesenchymal Transition: An Autopsy Case Report

A rare case of lung cancer with the simultaneous production of granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) is reported. A 79-year-old man was admitted to our hospital due to cachectic symptoms and an increased inflammatory response. Laboratory tests and imaging studies suggested metastatic lung cancer with high serum levels of G-CSF and IL-6. He died of progressive disease, and an autopsy showed that the lung tumor had positive protein expression of both cytokines and a solid growth of large-cell carcinoma with sarcomatoid changes, possibly resulting from the epithelial-mesenchymal transition mediated by IL-6 and leading to widespread metastases.