Ependymoma (Figure 2)
Demographics: Both children and adults.
Imaging: Heterogeneous signal intensities and enhancement with cystic/necrotic areas.
Pathology: Arises from ependymal lining of the ventricles, WHO grade II or III.
Most common location: Posterior fossa.
Surgical Approach: Suboccipital craniotomy and careful tumor resection sparing the cranial nerves.
Subependymoma (Figure 3)
Demographics: Most commonly occur between the fourth and sixth decades of life with male:female ratio of 2.3:1.
Imaging: Well-defined with calcification, T1 iso- and T2 hyper-intense, hypoenhancing lesion.
Pathology: Slow-growing, WHO grade I tumor arising from subependymal cells.
Most common location: Lateral and third ventricle.
Surgical Approach: Gross total resection (GTR), aims to relieve hydrocephalus.
Central Neurocytoma (Figure 4)
Demographics: Most frequently in younger and middle-aged adults between 20-40 years of age.
Imaging: Well-defined with peripheral calcifications and ‘soap bubble appearance’ on T2W MRI.
Pathology: Well-differentiated tumor, WHO grade II, in close contact with the septum pellucidum.
Most common location: Majority of them arise from the septum pellucidum or lateral ventricular wall.
Surgical Approach: Transcallosal endoscopic assisted resection.
Choroid plexus tumors (Figure 5)
Demographics: Accounting for <1% of all intracranial neoplasms; more frequent in children (2-4%) than in adults (0.5%).
Imaging: Enhancing ‘cauliflower appearance’, and may obstruct CSF pathways.
Pathology: Arises from choroid plexus epithelium, different histological types (papilloma, carcinoma).
Most common location: Ventricular atrium, 4th ventricle.
Surgical Approach: GTR, treating hydrocephalus.
Meningioma (Figure 6)
Demographics: Age distribution of 3rd to 6th decade of life with a mean age at diagnosis of 42.2 years.
Imaging: Well-defined, variable enhancement and signal intensities.
Pathology: Arises from arachnoid cap cells, usually benign (WHO grade I).
Most common location: Ventricular trigone.
Surgical Approach: Depends on tumor location and size, preferably GTR.
Colloid Cyst (Figure 7)
Demographics: Age distribution of 30 to 70 years of age at diagnosis, with rare cases reported as early as 1st year of life.
Imaging: Hyperintense on T1W MRI, often obstructs foramen of Monro.
Pathology: Gelatinous cyst lined with cuboidal or columnar epithelium.
Most common location: Anterosuperior aspect of the third ventricle attached to the fornix, near the foramen of Monro.
Surgical Approach: Endoscopic fenestration, piecemeal removal, aims to relieve hydrocephalus.
Epidermoid Cyst (Figure 8)
Demographics: Typically 3rd and 4th decades of life with a male to female ratio of 2:1.
Imaging: T1- and T2-isointense to cerebrospinal fluid, heterogeneous FLAIR signal and restricted diffusion.
Pathology: Thin capsule of squamous epithelium with internal cystic components, desquamated epithelial keratin and cholesterol crystals.
Most common location: 4th ventricle.
Surgical Approach: GTR via microsurgical transcortical, transcallosal, or endoscopic approaches.
Germinoma / Germ Cell Tumor (GCT) (Figure 9)
Demographics: Diagnosed at a mean age of 11.6 - 12.3 years and have a male to female ratio of 1.8 - 3.5:1.
Imaging: Well-defined, protruding into 3rd ventricle.
Pathology: Fluid-filled sac lined with arachnoid cells.
Most common location: Pineal region.
Surgical Approach: Frontal transcortical endoscopic assisted biopsy. GTR via infratentorial supracerebellar approach via suboccipital craniotomy.