Fatal Postoperative Pulmonary Tumor Thrombotic Microangiopathy: A Rare and Fulminant Complication of Large Cell Lung...

Pulmonary tumor thrombotic microangiopathy (PTTM) is a paraneoplastic pulmonary vascular process characterized by microscopic tumor emboli with fibrocellular intimal proliferation, causing rapid progressive pulmonary hypertension and right heart failure. We report a 72-year-old male with stage IIB large cell lung carcinoma who developed fulminant respiratory failure two months after curative-intent lobectomy, just prior to adjuvant chemotherapy. On presentation, he had multiorgan failure and disseminated intravascular coagulation with a markedly elevated D-dimer. Despite intensive supportive care, he died within hours. Autopsy confirmed PTTM with widespread tumor emboli occluding small pulmonary arteries and arterioles, together with previously unrecognized systemic metastases. This case illustrates that PTTM may precipitate catastrophic decompensation even soon after apparently curative surgery and supports maintaining a high index of suspicion for this syndrome in large cell lung carcinoma patients presenting with acute cardiorespiratory failure.