Numbers
- Constitute about 30% of all pineal tumours,
- Median age at presentation of 21 years
- M:F ratio: 1:1
Nomenclature
- Pineal regions tumour (Any tumour in the pineal region)
- Pineal parenchymal tumour
- Pineocytoma
- Pineal parenchgymal tumour of intermediate differentiation
- Pineoblastoma
- Papillary tumour of the pineal region is a separate entity
Pathology and genetics
- Most PPTs arise sporadically.
- Genetic alterations include
- Gains of chromosomes 4q2 and 12, and
- Losses of chromosomes 10 and 22
- PPTs are thought to arise from pineocytes
- PTPRs probably arise from ependymal circumventricular subcommissural organ cells and are distinct from PPTs.
- Histological diagnosis of primary pineal tumours is challenging and should be undertaken by experienced neuropathologists.
Types of pineal tumours
- Pineocytoma (WHO grade 1)
- Lower-grade tumours are more common in older adults
- Pineal parenchymal tumour of intermediate differentiation (WHO grade 2 or 3)
- Pineoblastoma (WHO grade 4)
- More common in younger children
- Rarely be associated with
- Bilateral retinoblastoma (5–13%) and
- Familial bilateral retinoblastoma (5–15%)
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