Learning objectives
A wide variety of lesions involve the pineal region,
including neoplasic and non neoplasic processes.
Tumors of the pineal region can be classified into those arising from the pineal parenchyma,
germ cell neoplasms and lesions arising from adjacent structures.
Overall they make up less than 1% of intracranial tumors in adults,
however pineal region neoplasms account for 3-8% of intracranial neoplasms in the pediatric population.
We propose to attend these objectives:
Provide a practical differential diagnosis of lesions of the pineal region,
with examples of...
Background
Lesions of the pineal region include a diverse group of entities.
Although they do not have pathognomonic imaging findings,
imaging in combination with laboratory evaluations sometimes helps narrow the differential diagnosis.
In order to interpret and understand the pineal lesions,
it is important to highlight the normal anatomy of the pineal region.
Then we will focus on signs and symptoms of pineal region masses and finally we will list the imaging features of lesions of the pineal region,
including tumors of pineal parenchymal origin,
germ...
Imaging findings OR Procedure details
1.
TUMORS OF PINEAL PARENCHYMAL ORIGIN
Pineal parenchymal tumors expand and obliterate pineal architecture,
“exploding” the normal pineal calcification toward the periphery.
1.1 Pineocytoma
At computed tomography (CT),
pineocytomas are well demarcated,
usually less than 3 cm,
and iso-to hyperattenuating (Fig 2).
At MR imaging,
pineocytomas are also well-circumscribed lesions that are hypo-to isointense on T1-weighted images and hyperintense on T2-weighted images.
On postcontrast images,
they typically demonstrate avid,
homogeneous enhancement.
1.2 Pineal Parenchymal Tumor of Intermediate Differentiation
No specific imaging findings separate PPTID from...
Conclusion
The differential diagnosis for pineal region lesions includes basically germ cell neoplasms and pineal cell neoplasms.
Germinoma and pineoblastoma,
have high attenuation at CT due to their high cellularity,
but if pineal calcification is seen the germinoma will tend to engulf it,
whereas in pineoblastomas it will be exploded to the periphery.
The presence of lipid or fat attenuation at CT leads to the differential diagnosis of a teratoma,
or lipoma.
Intrinsic increased T1 signal intensity may be seen in pineal parenchymal neoplasms or GCTs...
References
1.
Louis DN,
Ohgaki H,
Wiestler OD,
Cavenee WK.
WHO classification of tumours of the central nervous system.
Geneva,
Switzerland: World Health Organization,
2007.
2.
Surawicz TS,
McCarthy BJ,
Kupelian V,
Jukich PJ,
Bruner JM,
Davis FG.
Descriptive epidemiology of primary brain and CNS tumors: results from the Central Brain Tumor Registry of the United States,
1990-1994.
Neuro Oncol 1999;1(1):14–25.
3.
Smirniotopoulos JG,
Rushing EJ,
Mena H.
Pineal region masses: differential diagnosis.
RadioGraphics 1992;12(3):577–596.
4.
Smith AB,
Rushing EJ,
Smirniotopoulos JG.
Lesions of the pineal...