A case of primary lung squamous cell carcinoma mimicking malignant mesothelioma producing granulocyte colony stimulating factor with chemotherapy (cisplatin and gemcitabine)-associated thrombotic thrombocytopenic purpura (TTP); An autopsy case report.

OBJECTIVES: Thrombotic thrombocytopenic purpura (TTP) is a rare form of thrombotic microangiopathy. In recent years, an extensive variety of drugs, including certain cytotoxic agents, have been reported to be associated with TTP. Additionally, several studies have reported that granulocyte colony-stimulating factor (G-CSF) was produced by lung carcinoma. G-CSF-producing carcinoma also produces various other cytokines, which may cause vascular endothelial damage and trigger TTP development. However, there has been no report describing G-CSF-producing carcinoma combined with TTP. We report a rare case of pseudomesothliomatous squamous cell lung carcinoma producing G-CSF along with chemotherapy associated TTP. MATERIALS AND METHODS: A 66-year-old man with pseudomesotheliomatous primary squamous cell lung carcinoma was treated with chemotherapy consisting of cisplatin and gemcitabine as the first line treatment. However, thrombocytopenia, acute renal dysfunction and acute respiratory failure occurred after starting the first chemotherapy cycle. As a result, the patient died, and an autopsy was performed. RESULTS: According to the autopsy findings, a diagnosis of primary lung squamous cell carcinoma producing G-CSF associated with TTP was made. CONCLUSION: Chemotherapy-related TTP should be considered when anemia and thrombocytopenia progress rapidly in patients who are under chemotherapy treatment. Furthermore, the current case may provide a possible link between TTP and G-CSF-producing tumor.