Spontaneous hemothorax and neurofibromatosis type 1: How to explain it, how to explore it and how to treat it?

Neurofibromatosis type 1 (NF1), also known as Von Recklinghausen's disease is an autosomal dominant genetic disorder. It is the most common of phacomatoses. Pulmonary complications have been rarely described in the literature. It is generally a benign disease, but has the potential for rare and fatal complications, such as spontaneous hemothorax. We reported two cases of patients with a history of von Recklinghausen's disease. Both of them suffered sudden chest pain. Chest-X ray revealed a hemi-thoracic opacity. Enhanced chest computed tomography showed massive hemothorax, but no evidence of tumors or an obvious bleeding point in the thorax. After we had ensured a stable hemodynamic condition, we performed video-assisted thoracic surgery to remove the hematoma. No evidence of bleeding was noticed in the first patient whereas an active bleeding was observed in the second patient. We could not determine which vessel was responsible of the hemorrhage. Electrocoagulation and clot removal were performed.  Evolution was favorable for both patients. Spontaneous hemothorax is a rare and potentially life threatening NF1's complication. A tumor like neurofibroma or more rarely vascular involvement of large or small caliber arteries may be at hemothorax's origin.