Maximal Resection of Intramedullary Lipoma Using Intraoperative Ultrasonography: A Technical Note

One of the problems during surgery for intramedullary lipoma is the ambiguous boundary between the lipoma and the spinal cord, resulting in either incomplete resection or damage to the spinal cord. We report a case of intramedullary lipoma resection on a 61-year-old man in which the boundary between the tumor and spinal cord was repeatedly visualized with intraoperative ultrasonography. We focused on the distinctive features of fat as hyperechoic, in contrast to low-echo neural tissue. Subtotal resection of the tumor was achieved without any aggravation of neurological symptoms. Intraoperative ultrasonography may be useful for confirming tumor boundaries during intramedullary lipoma resection.