Pulmonary Tumor Thrombotic Microangiopathy Caused by Urothelial Carcinoma Expressing Vascular Endothelial Growth Factor, Platelet-derived Growth Factor, and Osteopontin

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal cancer-related pulmonary complication. It is generally caused by gastric adenocarcinoma, and several molecules produced by tumor cells are reported to play important roles in its pathogenesis. We herein report an autopsy case of PTTM caused by urothelial carcinoma. Vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and osteopontin were found to be expressed in both the primary tumor cells and metastatic cells in the PTTM lesions. These findings implicate the possible involvement of VEGF, PDGF, and osteopontin in the pathogenesis of PTTM caused by urothelial carcinoma.