Indicated if the tumor extends to the lateral ventricle.
The patient is placed in the supine position with the head at a 30° angle. The free 4-5 cm bone flap is placed over the central portion of the middle frontal gyrus and must be large enough to permit retraction of the middle frontal gyrus in two directions. The flap is based on the coronal suture, with the medial border 2 cm off the midline and the posterior border 2 cm behind the coronal suture. In cases with small ventricles, tumor in both lateral ventricles, and tumor in the body of the lateral ventricle, surgery may be better performed via a transcallosal route or a combination of approaches 1).