Fatal pulmonary tumor thrombotic microangiopathy caused by undiagnosed metastatic gastric adenocarcinoma.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare cause of rapidly progressive dyspnea in a background of metastatic cancer. Gastric adenocarcinoma is the neoplasm most frequently associated with PTTM. Unfortunately, PTTM is difficult to identify clinically and is most commonly a postmortem diagnosis. We present the case of a woman with no previous diagnosis of cancer who presented with rapidly progressive shortness of breath. She was diagnosed with severe pulmonary arterial hypertension and rapidly succumbed to her illness. A postmortem diagnosis of PTTM was established based on autopsy results.