SESSION TITLE: Critical Care Global Case Reports
SESSION TYPE: Global Case Report
PRESENTED ON: Tuesday, October 29, 2013 at 01:30 PM - 02:30 PM
INTRODUCTION: We describe the case of a patient with an unusual presentation of metastatic renal cell carcinoma with pulmonary tumor emboli and pulmonary tumor microangiopathy.
CASE PRESENTATION: A 63 year old male with no significant past medical history reported the onset of dyspnea on exertion, nonproductive cough, and weight loss three months prior to presentation at our medical center. He was treated empirically with inhaled bronchodilators and proton pump inhibitors. These therapies proved ineffective and his symptoms progressed. One month prior to presentation Chest CT demonstrated bilateral hilar and mediastinal adenopathy, ground glass opacities. Incidental note was made of an 11 cm complex left renal mass. Fiberoptic bronchoscopy with transbronchial biopsy of right middle lobe revealed cells with neuroendocrine features consistent with carcinoid tumorlets. One week prior to presentation he was admitted to an outside hospital with progressive dyspnea at which time he was noted to be hypoxic (85% on room air). CT angiogram (CTA) and lower extremity ultrasound were negative for venous thromboembolism. Transthoracic echocardiogram showed normal left ventricular function, dilated right atrium, and dilated right ventricle with reduced systolic function and septal flattening consistent with right ventricular pressure overload. He was transferred to our center for investigation into his pulmonary hypertension and hypoxia. At presentation he was hemodyamically stable, but hypoxic requiring 6-8 liters per minute of supplemental oxygen. Review of the CTA showed persistent adenopathy and diffusely increased interstitial markings bilaterally with prominent intralobular septae. Given echocardiographic evidence of pulmonary hypertension and right ventricular strain and the absence of a clear etiology, the patient was evaluated by the pulmonary hypertension team. Right heart catheterization was planned however, the patient’s respiratory status continued to decline, requiring initiation of non-invasive ventilation. He was transferred to the medical intensive care unit and was endotracheally intubated for hypoxic respiratory failure. Ten minutes following intubation, he experienced cardiopulmonary arrest and could not be resuscitated. Post mortem examination revealed metastatic renal cell carcinoma with massive engorgement of lymphatic channels by metastatic tumor, tumor emboli in pulmonary vessels, and invasion of metastatic tumor into alveolar spaces. Tumor was present focally in bronchial mucosa. Left lower lobe had multiple recent and organizing pulmonary vessel thrombi with associated hemorrhagic lung infarct. Peribronchial lymph nodes were positive for metastatic tumor. The left kidney was entirely replaced by a large necrotic tumor identified as papillary renal cell carcinoma.
DISCUSSION: Though premortem diagnosis of microscopic pulmonary tumor emboli and pulmonary tumor thrombotic microangiopathy is uncommon, up to 26% of cancer patients demonstrate pulmonary tumor embolism at autopsy. The clinical syndrome of progressive dyspnea, cough, hypoxia and chest pain are manifestations of subacute, and occasionally rapidly progressive, pulmonary hypertension. In addition to physical obstruction of the pulmonary bed with tumor, in situ thrombosis and fibrotic intimal hyperplasia have been described. Right ventricular failure ensues as the pulmonary vascular resistance rises. There are no specific therapeutic options for tumor emboli, outside of treatment of the underlying malignancy. Unfortunately given the challenges in recognizing this clinical syndrome, patients often present with advanced disease, and therefore efficacy is limited.
CONCLUSIONS: Pulmonary tumor emboli, although a rare entity, should be considered in any patient with a history of malignancy presenting with dyspnea, hypoxia, cough, or chest pain.
Reference #1: Schriner RW et al. Microscopic pulmonary tumor embolism causing subacute cor pulmonale: a difficult antemortem diagnosis. Mayo Clin Proc 1991;66:143-148
Reference #2: Franquet et al. Thrombotic Microangiopathy of Pulmonary Tumors: a vascular cause of tree-in-bud pattern on CT. AJR 2001; 179:897-899
Reference #3: Roberts et al. Pulmonary Tumor Embolism: A Review of the Literature. AmJMed 2003;115:228-232
DISCLOSURE: The following authors have nothing to disclose: Christopher Manley, Nadine Al-Naamani, Mahboubeh Rahmani, Stephen Naber, Erik Garpestad, Kari Roberts
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