Abstract
Pulmonary tumor thrombotic microangiopathy (PTTM) is a rapidly progressive fatal cancer-related complication. Diagnosing PTTM is challenging, with most cases diagnosed postmortem. Gastric, breast, and lung cancers are the most common primary tumors associated with PTTM. To the best of our knowledge, this is the first case report of PTTM arising from an endometrial carcinoma. A patient with advanced respiratory failure and pulmonary hypertension was diagnosed with endometrial carcinoma. This case highlights the importance of suspecting PTTM in patients with pulmonary hypertension accompanied by rapidly progressive dyspnea when pulmonary embolism has been excluded. In such cases, identifying the primary cancer is crucial for establishing an appropriate treatment plan. It also emphasizes the importance of investigating systemic cancers, extending beyond the frequently encountered cancers, even in the absence of active cancer. LEARNING OBJECTIVE: Pulmonary tumor thrombotic microangiopathy (PTTM) is a rapidly fatal complication of cancer. This is the first case report of PTTM arising from an endometrial carcinoma. Clinicians should consider PTTM in patients with respiratory failure and pulmonary hypertension, even in the absence of active cancer. Early investigation for underlying malignancy and prompt pathological evaluation are essential for the rapid diagnosis of PTTM.