Therapeutic challenges in transcatheter arterial embolization for an enlarging subcutaneous hematoma in a patient with neurofibromatosis type 1: A case report.

A 60-year-old woman with a history of neurofibromatosis type 1, who was admitted with pulmonary hypertension, developed buttock pain and anemia, and contrast-enhanced computed tomography showed a large subcutaneous hematoma with minimal active extravasation. Angiography of the bilateral internal iliac arteries revealed diffuse, irregular blood vessels without extravasation. As the exact bleeding site could not be identified, the patient was managed conservatively. However, the patient's symptoms and anemia worsened the following day. Repeat angiography revealed two pseudoaneurysms in the right inferior gluteal artery, which were embolized using n-butyl-2-cyanoacrylate. Nonetheless, the patient's anemia further worsened the following day. Repeat contrast-enhanced CT revealed another site of extravasation in the enlarging hematoma, but no extravasation was observed on the subsequent angiography. Owing to the worsening anemia and enlarging hematoma, proximal embolization of the irregular bilateral inferior gluteal arteries was performed using gelatin sponge particles. The patient's anemia and symptoms improved. Vasculopathy associated with neurofibromatosis type 1 is rare, with an incidence of approximately 3%. In patients with neurofibromatosis type 1, the blood vessels become fragile because of tunica media thinning and elastic-lamina rupture. Histopathologically, neurofibromatosis type 1-associated vasculopathy is characterized by a mixture of normal and abnormal vessels. Abnormally fragile blood vessels may repeatedly rupture followed by physiological hemostasis, which may explain the diagnostic and therapeutic challenges during angiography in this case. In patients with neurofibromatosis type 1 with acute bleeding, irregular vessels without active extravasation on angiography may be indicated for embolization.