A rare case of internal jugular vein aneurysm with massive hemorrhage in neurofibromatosis type 1.

Neurofibromatosis Type 1 (NF1) is a relatively common autosomal dominant disorder. Vascular involvement is a well-recognized manifestation of NF1, but venous aneurysm associated with NF1 is extremely rare. We present a case of an NF1 patient with a left internal jugular vein aneurysm with massive hemorrhage occurring during surgery. Due to the extreme fragility of both the aneurismal wall and the surrounding tissue, the patient developed severe intraoperative bleeding. Pathological examination confirmed aneurismal wall infiltration of the neurofibromatosis. Physicians should be aware that hemorrhagic complication in NF1 can occur and be fatal.