Learning objectives
To review the normal anatomy of the pineal region including the quadrigeminal cistern and adjacent structures.
To discuss pineal region mass lesions and their etiologies.
To discuss a systematic approach to narrow the differential diagnosis based on location,
age,
clinical presentation,
blood chemistry and imaging characteristics on different imaging modalities.
Background
The pineal gland is a small ( ~ 7mm) structure located at the level of the midbrain,
between the thalami at the posterior aspect of the third ventricle (Fig. 1).
The internal cerebral veins and vein of Galen are located superior and posterior to the pineal gland,
respectively.
These anatomic relationships can be helpful to determine if a mass is pineal or extra-pineal.
The principal neuronal cell of the pineal gland is the pinealocyte; a modified retinal neuronal cell that is innervated by the sympathetic...
Findings and procedure details
Approach to pineal region masses:
1) Determine if the mass is pineal or extra-pineal in origin (Fig. 2)
This can be done by evaluating the direction of mass effect on the internal cerebral veins and Vein of Galen.
This relationship will also affect surgical planning as follows:
If the tumor is below these veins,
a suboccipital infratentorial approach.
If the tumor is above these veins,
an interhemispheric or Sub temporal approach is used.
2) Age of the patient
3) Pattern of calcifications (if present)
4)...
Conclusion
The assessment of the pineal region isadequate with MRI witthe specific protocol.
Age,
calcification patterns,
MRI signal as well as determining whether the mass is pineal or extra-pineal are all importantin approaching a pineal region mass.
The mass effect on the internal cerebral veins and vein of Galen helps indetermining whether its a pineal gland or extra-pineal mass.
Germinomas and teratomas are the most common pineal gland tumors.
Personal information
Dr.
Haitham M.
Elsamaloty,
MD
Professor of Diagnostic Radiology
University of Toledo Medical Center
3065 Arlington Ave,
Toledo,
OH 43614
Email:
[email protected]
References
Osborn,
AG.
Diagnostic Imaging: Brain.
Salt Lake City: Amirsys,
2004.
Smirniotopoulos,
JG.,
et al.
Pineal Region Masses: Differential Diagnosis.
RadioGraphics 1992; 12:577-596.
Fujimaki,
T.,
Matsutani,
M.,
et al.
CT and MRI features of intracranial germ cell tumors.
J.
Neurooncol.
1994; 19:217-226.
Reis,
F.,
Faria A.,
et al.
Neuroimaging in Pineal Tumors.
J.
Neuroimaging 2006; 16:52-58.
Korogi,
Y.,
Mutsumasa,
T.,
et al.
MRI of pineal region tumors.
J.
Neurooncol.
2001; 54:251-255.