Spontaneous bilateral hemothorax in neurofibromatosis type 1 due to internal thoracic artery aneurysm: Case report

•In patients with NF1, the risk of spontaneous bleeding due to the possibility of aneurysmal formation should be considered.•The differential diagnosis of neurofibromatosis should be investigated in cases of spontaneous hemothorax.•In most cases of spontaneous hemothorax associated with NF1, intercostal artery aneurysm is the most common injury. Vascular lesions are associated with neurofibromatosis 1, including stenosis and aneurysms. A 43-year-old man presented with sudden respiratory failure in our emergency medical service. Physical examination suggested diagnosis of neurofibromatosis. Chest computed tomography revealed a sizeable bilateral hemothorax. He was then submitted to arteriography, which evidenced the right internal thoracic artery aneurysm. The aneurysm was selectively catheterized and embolized, followed by a video-assisted thoracoscopy surgery to drain the hemothorax. The bleeding dissected to both pleural cavities, causing the bilateral hemothorax. Although the patient did not have a medical diagnosis of neurofibromatosis before the occurrence, the presence of clinical signs of the disease, associated with the exclusion of other causes for hemothorax, allowed differential diagnosis and appropriate treatment. The differential diagnosis of neurofibromatosis should be advanced in cases of spontaneous bleeding. In patients diagnosed with neurofibromatosis, the risk of spontaneous bleeding due to the possibility of aneurysmal formation should be considered.