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A1791 - A Case of Spontaneous Hemothorax in a Man with Neurofibromatosis Type 1
Author Block: R. Sidhom1, F. A. Youssef2, M. A. Tanios3; 1Internal Medicine, University of California, Irvine, Orange, CA, United States, 2Pulmonary and Critical Care, University of California, Irvine, Orange, CA, United States, 3Pulmonary and Critical Care, Long Beach Memorial Hospital, Long Beach, CA, United States.
Introduction:
Neurofibromatosis Type 1 (NF1) is an autosomal dominant disorder involving a mutation encoding the Neurofibromin protein. This gene is utilized throughout multiple tissues derived from neural crest and mesodermal cell lines. 6 Well known manifestations include skin lesions, neurofibromas, gliomas, and meningiomas. NF1 has been known to affect vascular structures leading to aneurysms and spontaneous hemorrhage. We present a case of a male with NF1 and spontaneous hemothorax.
Case:
70-year-old male with NF1 presenting with acute right-sided flank pain, dyspnea and syncope. Medical history includes NF1, atrial fibrillation, prostate cancer, and hypertension. Family, social, and surgical histories were unremarkable. Significant medications include Metoprolol Tartrate, Lisinopril, and Flecainide. Vital signs were notable for hypotension (89/57), tachycardia (127), and tachypnea (33). CT Chest Angiogram revealed a loculated right pleural effusion occupying >60% of the hemithorax and right lower lobe collpase. Thoracentesis yielded 1.5L of thick bloody fluid. No pulmonary embolism, pneumonia, parenchymal lung disease, or trauma were found to explain spontaneous hemothorax. Patient subsequently suffered cardiopulmonary arrest and was resuscitated. Hemoglobin at that time was 6.1 with a lactate of 14.8. A chest tube was placed and another 1.2L of bloody fluid was removed. Patient was supported with 3 vasopressors, broad-spectrum antibiotics, mechanical ventilation, and transfusion of 3 units packed red blood cells. We feel his hemothorax was secondary to a ruptured intrathoracic aneurysm brought about by his underlying NF1. No responsible lesion was found and it was believed that the hemorrhage had self-resolved. He recovered and eventually underwent tracheostomy. His course has been complicated by renal failure requiring hemodialysis and recurrent Clostridium difficile colitis. No recurrent episodes of hemorrhage have occurred.
Discussion:
Vascular involvement of NF1 is present in 3.6% of patients. Manifestations include vascular stenosis, aneurysm, and arteriovenous fistula.1,3,4 In large arteries, neurofibromatous tissue results in intimal proliferation and eventual fragmentation of the elastic layer and weakening of the muscle walls leading to aneurysm.2 In smaller arteries, dysplasia of the vessels themselves, and not neural malformation, leads to weakening.5 A case series from Japan documented 12 instances of spontaneous hemothorax in patients with NF1 with 50% mortality. Arteries involved included; intercostal, subclavian, internal thoracic, and innominate.7 Arterial embolization is the first-line treatment in these situations.1,3 This case illustrates the importance of recognizing the association of NF1 and spontaneous hemothorax in adults presenting with hemodynamic instability and chest pain given the significant morbidity and mortality associated with a delated diagnosis.