Pineoblastoma is a rare, aggressive tumor of the pineal region. Pineoblastomas consist of immature, undifferentiated cells and are histologically classified as primitive neuroectodermal tumors.
Epidemiology
Pineoblastomas are rare tumors and account for approximately < 0,1% of all intracranial tumors1. They occur predominantly in childhood and show no sex predilection or, at most, a slight male predilection2.
Imaging
On MRI, the tumors are usually isointense to the gray matter on T1- and T2-weighted images3. After contrast administration, they show intense enhancement4. The margins are often indistinct, and hemorrhage, melanin deposition, cysts, and surrounding cerebral edema in cases of parapineal growth are common.
The primary imaging differential diagnosis is germinoma5.
Metastasis
Pineoblastomas can metastasize along the cerebrospinal fluid circulation. Peritoneal metastases following implantation of a VP shunt have also been described in the literature6 7. Metastasis outside the CNS is uncommon and occurs in < 0,5% of patients; these figures include the potential facilitation of metastasis by surgical procedures and VP shunt placement8 9.
Prognosis
The prognosis of pineoblastoma can vary considerably. Overall, the prognosis is poor, as the tumors disseminate into the cerebrospinal fluid spaces at an early stage10. Studies suggest that pineoblastomas show a more aggressive course in younger patients11.
References
Tate, Matthew, et al. "The long‐term postsurgical prognosis of patients with pineoblastoma." Cancer 118.1 (2012): 173-179. ↩ ↩ ↩ ↩
Mader, Irina, Wolfgang Grodd, and Thomas Nägele. "The differential diagnosis of tumors of the pineal region using magnetic resonance imaging." Klinische Neuroradiologie 11.1 (2001): 25-32. ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩
Gururangan, Sridharan, et al. "Peritoneal metastases in two patients with pineoblastoma and ventriculo‐peritoneal shunts." Medical and pediatric oncology 22.6 (1994): 417-420. ↩ ↩
Cranston, Philip E., Margaret T. Hatten, and Edward E. Smith. "Metastatic pineoblastoma via a ventriculoperitoneal shunt: CT demonstration." Computerized medical imaging and graphics 16.5 (1992): 349-351. ↩ ↩
Fraser, G., Rampling, R., Smith, C. et al. Long-term Survival Following Extra-neural Metastasis From a Pineoblastoma. J Neurooncol 48, 141–144 (2000) ↩ ↩
Liwnicz, Boleslaw H., and Lucien J. Rubinstein. "The pathways of extraneural spread in metastasizing gliomas: a report of three cases and critical review of the literature." Human pathology 10.4 (1979): 453-467. ↩ ↩