The goal of treatment in tectal plate gliomas is to reverse the signs and symptoms of hydrocephalus and improve neurologic deficits and to prevent further neurologic damage [10]. One of the earliest treatment options is shunting of cerebrospinal fluid to peritoneum via a ventriculoperitoneal (VP) shunt [26].

Pollack al. [18] describe hydrocephalus for this group of patients to be more challenging than the usual hydrocephalic patient.

18.75 % of the patients (3 out of 16) in this report developed subdural hematomas.

Chapman [27] encountered similar problems in his shunted cases with 28.57 % (2 out of 7) cases resulting in subdural hematomas. Subsequent management is open-ended follow-up with neuroimaging. The second option is endoscopic third ventriculostomy (ETV). It is the gold standard for the management of hydrocephalus induced by tectal plate gliomas (Fig. 32.3a–d) and additionally allows the surgeon to take a biopsy from the lesion [28–30]. The third but less frequently used option is endoscopic aqueductoplasty with or without stenting [10].

There are well-described safe and unsafe entry zones for open midbrain surgery [31]. It is advocated to use supracollicular incision, infracollicular incision, and lateral mesencephalic sulcus to enter the mesencephalon, whereas it is not advised to use incisions through superior and inferior colliculi [31].

The lesions in the tectal plate can be reached easily by occipital transtentorial and infratentorial supracerebellar approaches.

Occipital transtentorial approach has been adopted by many neurosurgeons for tumors located in this region, to avoid possible damage to colliculi (Fig. 32.4a–d). In this approach a right occipital craniotomy is performed and tentorium is incised just adjacent to the straight sinus. The direct visualization of the fissure between the superior vermis, quadrigeminal plate, and superior medullary velum is the advantage, whereas a probable visual defect resulting from occipital lobe retraction is the disadvantage of this approach [32, 33]. The same area can be also easily reached through standard infratentorial supracerebellar approach which is first described for pineal region tumors [33, 34]. Infratentorial supracerebellar approach can be used for more caudally located median tumors with infracollicular entry to avoid ocular and auditory disturbances [32]. Ternier et al. [35] centered their decision based on tumor volume. Tumors less than 4 cm³ are less likely to progress (hamartomas); lesions with volumes greater than 10 cm³ warrant consideration for an early intervention. Those in between, 4–10 cm (hamartomas or tumors), will benefit from frequent initial imaging.

Possibility exists that the majority of these tumors increase and cause new deficits; thus, diligent long-term follow-up becomes a part of the armamentarium of the surgeon. Pollack et al. [14] recommend MR imaging and clinical examinations every 6 months for the 1st year after the diagnosis and then yearly for 4 years in patients who are asymptomatic. From the 6th year onwards, yearly clinical evaluation is sufficient and imaging studies are obtained every 2–3 years or in the interim if new symptoms develop. It is vital that the patients are warned there is a possibility of tumor progression (6.9 years from shunt insertion and 11.5 years from the onset of initial symptoms) in a certain percentage of patients, despite the so-called indolent nature of their tumors, and hence not to neglect follow-up [14].

Tumors arising from the tegmentum may extend upward to the thalamus or downward to the pons. They displace but do not infiltrate intrinsic mesencephalic nuclei and tracts although they may reach enormous size so that they may be candidates for surgical resection (Figs. 32.6a–c, 32.7a–c, and 32.10a–c) [32].

They are almost always focal low-grade astrocytomas. Therefore, total excision should be the aim for surgery of these tumors.