Tumors of Pineal Cell Origin

Tumors of pineal cell origin are rare intracranial lesions. They are the second most common entity encountered in the pineal gland, after tumors of germ cell origin. They are classified according to their differentiation in pineocytomas (World Health Organization [WHO] grade I tumor), pineal parenchymal tumors of intermediate differentiation, papillary tumors of the pineal region, and pineoblastomas (WHO grade 4 tumor). Differentiation between pineal and germ cell tumors is essential, and for this purpose serum and cerebrospinal fluid (CSF) markers are used, alongside imaging techniques. Often, the only way to differentiate these two types of tumors is through a biopsy, which may be carried out with or without a simultaneous third ventriculocisternostomy. Retrospective series show an association between the extent of resection and improved outcomes, and benign lesions may be cured by performing a gross total resection. However, the approaches to this region are highly complex, because of the plethora of essential neuroanatomical structures in the area. The approaches need to be tailored to the specific anatomy of the patient and should aim at minimizing surgical morbidity. Because of their complexity, these lesions should mainly be performed in centers with sufficient experience in the treatment of pineal region lesions.