Masses in the pineal region have a relatively broad differential because of the variety of cell types found in the region.
The term pinealoma was historically used to refer to both pineal parenchymal tumors and germinomas, which are the two most common categories of primary pineal region tumors 6. Germinomas were sometimes called the "two-cell" pattern type of pinealoma, due to the presence of both lymphocytes and neoplastic germ cells that were reminiscent of teratomas 6. The term pinealoma has since fallen in popularity.
Some lesions (such as cysts) are typically discovered incidentally but for larger lesions, patients present clinically with symptoms related to mass effect. Compression of the tectal plate may cause a defect in up-gaze (Parinaud syndrome). Compression of the cerebral aqueduct may cause obstructive hydrocephalus.
Intrinsic pineal tissue masses tend to cause upward displacement of the internal cerebral veins. This is in distinction to tentorial meningiomas, which depress the cerebral veins.
- pineal cyst (most common benign pineal region mass)
- germ cell tumors
- pineal parenchymal tumors (~30% of primary pineal region tumors)
- glioma (usually tectal in origin, astrocytic in histology) (~5% of primary pineal region tumors)
- pineal metastasis
- primary pineal malignant melanoma 5
- inclusion cysts (dermoid/epidermoid) 4
- meningioma near the pineal region
- rare vascular lesions
If invasive, a tectal plate mass may be difficult to distinguish from a pineal mass.
- 1. Smirniotopoulos JG, Rushing EJ, Mena H. Pineal region masses: differential diagnosis. Radiographics. 1992;12 (3): 577-96. Radiographics (abstract) - Pubmed citation
- 2. Hayashida Y, Hirai T, Korogi Y et-al. Pineal cystic germinoma with syncytiotrophoblastic giant cells mimicking MR imaging findings of a pineal cyst. AJNR Am J Neuroradiol. 2004;25 (9): 1538-40. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 3. Ganti SR, Hilal SK, Stein BM et-al. CT of pineal region tumors. AJR Am J Roentgenol. 1986;146 (3): 451-8. AJR Am J Roentgenol (abstract) - Pubmed citation
- 4. Wolfgang Dähnert. Radiology Review Manual. (2011) ISBN: 9781609139438
- 5. Park JH, Hong YK. Primary malignant melanoma in the pineal region. (2014) Journal of Korean Neurosurgical Society. 56 (6): 504-8. doi:10.3340/jkns.2014.56.6.504 - Pubmed
- 6. Louis DN. A half century of change in diagnostic neuropathology: from the giants of yore to current brain tumor classification. (2020) Human pathology. 95: 161-168. doi:10.1016/j.humpath.2019.06.006 - Pubmed
Related Radiopaedia articles
Pineal region masses
The pineal region is anatomically complex and plays host to a number of unique masses and tumors as well as potentially affected by many entities seen more frequently elsewhere in the brain.
- cystic non-neoplastic lesions
- pineal parenchymal tumors
- germ cell tumors
- tumors also encountered in the pineal region
- pineal gland metastases
- vascular lesions