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Pineocytoma

Last Updated: March 27, 2020

Figure 1: A mass in the pineal region is causing obstructive hydrocephalus on this CT image (top row left). There is mass effect on the tectal plate without visible invasion on the sagittal T1WI (top row right). Avid enhancement on sagittal post-contrast T1WI (bottom) is typical of most pineal-region tumors including this pineocytoma, regardless of grade.

Figure 2: This circumscribed pineocytoma in the demonstrates peripheral calcifications (arrow) and homogeneous enhancement on post-contrast CT. The lesion is more circumscribed and less infiltrative in appearance than would be more typical for other pineal-region tumors.

Basic Description

  • Slow-growing pineal parenchymal tumor

Pathology

  • WHO grade I or II
  • Arises from pineocytes or pineocyte precursors
  • Well-differentiated tumor without mitoses or necrosis
  • Small, uniform cells arranged in sheets with intervening septae are typical microscopic features
  • Mass effect on adjacent structures without invasion

Clinical Features

  • Affects all ages (mean 35-40 years old)
  • No gender predilection
  • Commonly presents with signs/symptoms of increased intracranial pressure secondary to 3rd and lateral ventricular obstructive hydrocephalus
    • Headache, nausea, vomiting, and altered mental status
    • Parinaud syndrome (upgaze palsy)
  • Treatment: surgical resection; CSF shunts for hydrocephalus
  • Prognosis: Better prognosis than pineoblastoma; 5-year survival 85-100%

Imaging Features

  • General
    • Peripherally-calcified, well-circumscribed pineal region mass
    • Usually smaller size than pineoblastomas (<3 cm), less invasion of adjacent parenchyma
    • Calcification and cysts are often present
    • ± Obstructive hydrocephalus due to compression at the cerebral aqueduct
    • Rare intraventricular extension, CSF dissemination or parenchymal invasion
  • CT

    • Well-circumscribed, iso- to hypodense pineal mass
    • ± Peripheral calcification
    • Moderate enhancement on contrast-enhanced CT
  • MRI

    • T1WI: hypo- to isointense
    • T2WI: hyperintense
    • FLAIR: hyperintense
    • T2*GRE/SWI/GRE: black signal blooming in foci of calcification at the periphery of the tumor
    • T1WI+C: variable enhancement

Imaging Recommendations

  • MRI without and with IV contrast, CT to detect calcification

For more information, please see the corresponding chapter in Radiopaedia.

Contributor: Rachel Seltman, MD

DOI: https://doi.org/10.18791/nsatlas.v1.ch02.1.16

References

Awa R, et al. Neuroimaging diagnosis of pineal region tumors-quest for pathognomonic finding of germinoma. Neuroradiology. 2014;56:525-534.

Deshmukh VR, et al. Diagnosis and management of pineocytomas. Neurosurgery. 2004;55:349-355; discussion 355-357.

Dumrongpisutikul N, et al. Distinguishing between germinomas and pineal cell tumors on MR imaging. AJNR Am J Neuroradiol. 2012;33:550-555.

Hirato J, et al. Pathology of pineal region tumors. J Neurooncol. 2001;54:239-249.

Nakamura M, et al. Neuroradiological characteristics of pineocytoma and pineoblastoma. Neuroradiology. 2000;42:509-514.

Osborn AG, Salzman KL, Jhaveri MD. Diagnostic Imaging (3rd ed). Philadelphia, PA: Elsevier, 2016.

Reis F, et al. Neuroimaging in pineal tumors. J Neuroimaging. 2006;16:52-58.

Schild SE, et al. Pineal parenchymal tumors. Clinical, pathologic, and therapeutic aspects. Cancer. 1993;72:870-880.

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