Technical Note & Surgical TechniqueSkull bone tumor resection with intraoperative indocyanine green fluorescence imaging: A series of four surgical cases

•Four patients underwent surgical treatment for skull bone tumor.•Intraoperative ICG fluorescence was useful for skull bone tumor resection for visualizing bone tumor hidden in normal bone tissue.•In all cases, total tumor resection with the appropriate margin was achieved.

BackgroundSkull bone tumor resection is sometimes difficult, when tumor is hidden under the bone surface or similar to the normal bone in appearance. Indocyanine green (ICG) fluorescence has been used in various surgical fields for visualizing vascular and tumor tissues. This is the first report to show that intraoperative ICG fluorescence is useful for skull bone tumor resection.Case descriptionFour patients underwent skull bone tumor resection from June to December 2014. Two patients had Langerhans cell histiocytosis, and the others had hemangiomas. During surgical treatment, intraoperative ICG injection revealed the bone tumors hidden in normal bone tissue in real time. Three of the four tumors were identified as a high intensity area, and the other, a cavernous hemangioma, as an area lacking fluorescent enhancement. Each area was marked and then removed en bloc with an outside margin of 1 cm. On pathological examination, the surgical margin corresponded to the actual margin. In all cases, Postoperative course was uneventful, and there was no tumor recurrence.ConclusionOur experience illustrates that intraoperative ICG fluorescence examination might be a useful supplemental method for skull bone tumor resection, especially for tumors extending under the bone surface or similar to normal bone in appearance.