Resection of tumors in the third ventricle refers to tumors that originate from the internal structures of the third ventricle or tumors that originate from adjacent structures and protrude largely into the third ventricle. Resection of tumors in the anterior, middle or posterior third ventriclevia is a difficult and dangerous operation in the field of neurosurgery, and the choice of the surgical approach is particularly important. The clinical symptoms are headache, memory loss, visual field loss, psychiatric symptoms, endocrine dysfunction, speech impairment, and motor or sensory impairment due to intracranial hypertension. The tumor was removed through an interhemispheric transcallosal approach via the anterior mediastinal corpus callosum. The middle part of the third ventricle and the structures in the middle of the third ventricle were revealed by entering the third ventricle. Adjusting the microscopic angle, the anterior structures of the third ventricle such as the end plate and hypothalamus can be revealed forward, and the dorsal saddle, Willis ring and basilar artery can be revealed after tumor resection; the posterior structures of the third ventricle such as the midbrain aqueduct and pineal region can be revealed backward. The tumor is resected mainly by intracapsular resection, and the tumor wall is gradually separated, and important structures such as internal cerebral veins, thalamus and hypothalamus are protected during the operation. After the operation, a fistula was performed at the base of the third ventricle to stop the bleeding and place intracerebroventricular drainage. The anterior longitudinal approach to the corpus callosum to remove the tumor of the third ventricle is performed in the supine position with the head 20° high, with the coronal suture as the posterior border and the medial line as the bone flap formed by the medial border, separating the longitudinal fissure, revealing the bilateral pericallosal arteries 1E Separating the pericallosal arteries to reveal the corpus callosum, the lateral ventricles, the bilateral internal cerebral veins and their surface covering the arachnoid membrane, the bilateral internal cerebral veins are incised between them, and the third ventricle is entered from between the domes, the third ventricle, anteriorly for the fistula opening at the base of the third ventricle, and posteriorly for the opening of the midbrain aqueduct. The anterior, middle and posterior portions of the third ventricle can be reached through the anterior longitudinal corpus callosum approach, and the tumor can be removed under direct vision with a high rate of total resection. This approach makes full use of the avascular area on the brain surface, the natural gap between the bilateral pericallosal arteries and internal cerebral veins, and the natural space of the ventricles, creating favorable conditions for the exposure and resection of deep brain lesions. Compared with other third ventricular approaches, this approach has a large direct view angle and can expose a considerable area of the anterior, middle and posterior third ventricle; in addition, it has less impact on the blood vessels, especially the cortical drainage veins. MRI confirmed that the total resection rate in this group of cases was above 80%, which was related to this surgical approach and intraoperative tumor exposure, but also to the type of pathology in this group of cases. Craniopharyngiomas, germ cell tumors, cysts and meningiomas were predominant, with well-defined borders, which were easy to separate and complete resection. The incidence of postoperative hydrocephalus in the third ventricle tumor ranged from 11% to 40% regardless of the presence or absence of preoperative hydrocephalus and whether ventriculoscopy or craniotomy was adopted. Tumor resection combined with concurrent third ventricular floor fistula has a significant alleviating effect on hydrocephalus. Stereotactic radiotherapy combined with third ventricular floor fistula is now the routine procedure for smaller tumors in the third ventricle and when germ cell tumors are suspected. The transverse longitudinal corpus callosum approach allows for resection of the third ventricle tumor and simultaneous anterior third ventricle exposure and fistula without additional trauma compared to other approaches. The incidence of postoperative interictal epilepsy is higher with a transcortical approach to intracerebroventricular surgery and has been reported in the literature to be 6% to 70%. However, the incidence of interictal epilepsy has been reported to be as high as 25% with a transcallosal approach in third ventricle surgery. In the corpus callosum approach, the incised tissues are white matter fibers, and the occurrence of epilepsy should be related to excessive traction of the longitudinal fissure and damage to the cortical surface drainage veins. Setting the bone window at and before the coronal suture is slightly different from setting the window 2 cm posterior to the coronal suture. The area inside the window before the coronal suture is a “avascular zone” without cortical drainage veins, which, combined with a stable intraoperative retractor, reduces the extent of cortical vein damage and thus the incidence of interictal epilepsy. The disadvantage of the transverse longitudinal corpus callosum approach is that it is more difficult to deal with the area of the anterior third ventricle involving the base of the frontal lobe because of the limited angle of incision between the corpus callosum and the dome. Patients with corpus callosum incision may suffer from postoperative loss of union syndrome, loss of reading, loss of recognition, and loss of discrimination. Woiciechowsky et al. reported that a corpus callosotomy length of less than 22 mm did not result in permanent loss-of-union syndrome. In conclusion, the anterior longitudinal corpus callosum approach can expose the anterior, middle, and posterior third ventricle tumors and allow surgical resection. This approach has a low vascular impact and allows the surgeon to remove the tumor under direct vision, resulting in a high rate of total surgical resection. The combination of intraoperative third ventricular floor fistula provides fewer postoperative complications and good outcomes.