Tumor Embolism Presenting as Rapidly-forming Cavitary Lesion

Abstract

Cavitary lung lesions are most often associated with infectious processes, but cavities can develop rapidly in the setting of pulmonary infarction due to venous thromboemboli or malignant necrosis most comonly due to squamous cell carcinoma. Venous tumor embolism occurs when tumor cells invade the vasculature and then disseminate. Initial symptoms of tumor emboli to the lungs are typically similar to those of non-malignant pulmonary thromboembolism including dyspnea, hypoxemia, and normal or minimally abnormal chest radiography, but may also include progressive pulmonary hypertension and cor pulmonale. Definitive diagnosis can be made via lung tissue biopsy or demonstration of malignant cells from blood samples aspirated from the distal port of a wedged pulmonary artery catheter. We report the case of a patient who developed rapidly-developing, large lung cavities due to diffuse tumor emboli. A 64 year-old man with a history of lung adenocarcinoma previously treated with lobectomy and chemotherapy was admitted with respitatory distress. He was tachycardic and hypoxic on presentation. Imaging studies revealed a small pulmonary embolus within the pulmonary artery supplying the left upper lobe as well as two large right-sided pulmonary cavities which were not present on outpatient imaging just one week prior. Laboratory studies revealed leukocytosis and abnormal liver enzymes but no definitive evidence of infectious or autoimmune pathology. Despite treatment with systemic anticoagulation and broad-spectrum antibiotics, he developed progressive respiratory failure as well as neurologically-devastating cerebral ischemic events. After discussion with his family, he was transitioned to comfort care and died shortly thereafter. Post-mortem examination revealed widespread occlusion of pulmonary vessels with malignant cells, including the vessels supplying the areas of the lung containing the cavities. Histopathologic staining was consistent with adenocarcinoma. Non-malignant thromboemboli were not found on gross or microscopic examination of his lung vasculature. He also had neoplastic involvement of the vessels in his splanchnic circulation. We believe that widespread tumor emboli caused his pulmonary cavities, respiratory failure, and neurologic deterioration. doi:10.4021/jmc263w