Pineal region mass

Last revised by Tom Foster on 9 May 2023

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.

Many pineal region lesions, especially small ones that do not significantly change in size, such as cysts, are typically discovered incidentally. For larger lesions, patients often present clinically with symptoms related to mass effect. Compression of the tectal plate may cause an upward gaze palsy (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.

If invasive, a tectal plate mass may be difficult to distinguish from a pineal mass.

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