[Operative approach to a dumbbell-shaped tumor in the anterior cranial fossa. A case of olfactory neuroblastoma].

We present a case of giant olfactory neuroblastoma with special reference to a new operative approach in cases of dumbbell-shaped tumor in the anterior cranial fossa. Our new approach is characterized as follows: resection of the bilateral orbital roof and frontal sinus en bloc, following bifrontal conventional craniotomy. Accordingly, retraction of the frontal lobe is minimized and it is possible to obtain, with ease, a good operative field extending to the region adjacent to the tuberculum sellae. Using this technique combined with the transsphenoidal approach, even in the case of marked extracranial downward extension of a dumbbell-shaped tumor, it should be possible to remove the tumor totally. This approach should open a way to a wide range of application.