When we analyze a potential brain tumor, many questions need to be answered.
Since different Brain Tumor happen in different age groups, we first of all need to know the age of the victim.
Next, we require to know where the lesion is established – is it intra- or extra-axial, and in what anatomical part does it lie?
Is it established in the sellar or pontocerebellar region, for example?
Is it a single mass, or is there a multi-focal disorder?
On MR and CT, we look for tissue components like calcifications, fat, cystic elements, contrast improvement, and signal intensity on T1WI, T2WI, and DWI.
Most brain tumors are of low signal strength on T1WI and high on T2WI.
Therefore high signal intensity on T1WI or low signal on T2WI can be a necessary clue to the diagnosis.
Finally, we have to consider the opportunity that we are dealing with a lesion that affects a tumor-like an ulcer, MS-plaque, vascular malformation, aneurysm, or an infarct with luxury perfusion.
Incidence of CNS tumors
Roughly one-third of CNS tumors are metastatic lesions, one third are gliomas, and one-third is of non-glial origin.
Glioma is a non-specific term meaning that the tumor originates from glial cells like astrocytes, ependymal, oligodendrocytes, and choroid plexus cells.
Astrocytoma is the most common glioma and can be divided into the low-grade pilocytic type, the standard anaplastic type, and the high-grade malignant glioblastoma multiforme (GBM).
GBM is the most common type (50% of all astrocytomas).
The non-glial cell tumors are a large heterogeneous group of tumors of which meningioma is the most common.
Although cancer is rare in children, brain tumors are the most common type of childhood cancer after lymphoma and leukemia.
Most of the tumors in kids are located infratentorial.
The most popular supra- and infratentorial tumors are listed in the report on the left.
The most regular tumors in adults are listed in the table on the left.
Note that metastases are by far the most common.
It is essential to realize that 50% of metastases are solitary.
Particularly in the posterior fossa, metastases should be in the top 3 of the differential diagnostic list.
Hemangioblastoma is an unusual tumor, but Brain Tumor is the most popular primary intra-axial tumor in the adult.
Supratentorial, metastases are also the most common tumors, followed by gliomas.