Pulmonary Tumor Thrombotic Microangiopathy Induced by Ureteral Carcinoma: A Necropsy Case Report

BACKGROUND: Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal cancer-related pulmonary complication with rapidly progressing dyspnea and pulmonary hypertension that occasionally induces sudden death. We report the first case of PTTM induced by ureter carcinoma. CASE PRESENTATION: The patient was an 80-year-old Japanese female with chief complaints of dry cough and dyspnea. An echocardiogram revealed severe pulmonary hypertension. A chest radiograph showed ground glass opacity of bilateral lower lung field predominance, and an abdominal computed tomography scan revealed a left ureter mass suggestive of ureter carcinoma. The patient died of respiratory failure on the eighth day of hospitalization. Postmortem examination indicated that the primary lesion was a left ureter cancer with tumor microemboli extending to both lungs through the right side of the heart. The final diagnosis of this case was PTTM induced by ureter carcinoma. CONCLUSION: The pathogenesis and pathophysiology of PTTM remains obscure with no effective management available. In cases of rapidly progressing respiratory failure with pulmonary hypertension, it is necessary to consider PTTM in the differential diagnosis.