Neoplasia Flashcards
(13 cards)
What is the origin of extra-axial brain masses?
Peripheral location, compress rather than invade, more likely to contrast enhance, may have concurrent changes to skull, broad-based contact with meninges
Extra-axial masses are less protected by the blood-brain barrier (BBB) and may exhibit a dural tail sign.
What characterizes intra-axial brain masses?
May be completely surrounded by normal brain tissue, can contact overlying meninges, variable contrast enhancement
They may produce an acute angle or ‘claw sign’ when in contact with meninges.
List some associated findings with intracranial masses.
- Hydrocephalus
- Syringomyelia
- Perilesional edema
- Mass effect
- Brain herniation
These findings indicate complications arising from the presence of a mass in the cranial cavity.
What MRI signs are significantly associated with neoplasia?
- Single lesion
- Shape
- Mass effect
- Dural contact
- Dural tail
- Lesions affecting adjacent bone
- Contrast enhancement
These signs help radiologists in diagnosing brain tumors.
Name the MRI signs predictive of neoplasia.
- Strong contrast enhancement
- Extra-axial origin
- T2 FLAIR mixed intensity
- Defined lesion margins
These predictive signs are crucial in differentiating neoplastic lesions from other brain conditions.
Describe the characteristics of meningiomas.
- Round/ovoid or plaque-like
- Broad-based contact with underlying bone
- Usually single lesion
- T1 hypo/iso intense, T2/FLAIR hyperintense, strongly contrast enhancing
Meningiomas often exhibit a dural tail sign and can cause mass effect and edema.
What are common findings in glioblastoma multiforme?
- Sharply marginated or diffuse intra-axial
- Heterogenous T2 hyperintense
- T1 iso/hypointense
- Variable contrast enhancement
- Concurrent necrosis, peritumoral edema, mass effect, and cyst-like changes
These features can help distinguish glioblastomas from other tumor types.
What is the typical location of choroid plexus tumors?
Most commonly in the 4th ventricle, followed by 3rd and lateral ventricles
Choroid plexus tumors often present as papilloform or globular ventricular masses.
What are the MRI characteristics of ependymomas?
- Fairly well-circumscribed smooth or lobulated mass
- T1 isointense, T2 hyperintense, variably contrast enhancing
- Associated with cyst-like structures
Ependymomas arise from ependymal cells lining the ventricles.
What defines hamartomas?
Masses formed by disorderly overgrowth of tissue elements normally present at that site
Meningioangiomatosis is a rare benign lesion that can present in conjunction with hamartomas.
How do pituitary macrotumors typically appear on MRI?
- Oval or irregular mass measuring more than 10mm
- Variable signal intensity, commonly isointense on T1, mildly hyperintense on T2
- Strongly homogenously or heterogeneously contrast enhancing
Larger tumors have worse prognosis for radiation therapy.
True or False: Intravascular lymphoma presents as multifocal small parenchyma T2/FLAIR hyperintense lesions.
True
These lesions are consistent with infarcts and may show variable contrast enhancement.
Fill in the blank: Gliomatosis cerebri is characterized by _______.
[diffuse widespread infiltration of glial cells]
This condition typically does not enhance with contrast and affects several adjacent cerebral lobes.
