Brain tumors Flashcards
What is the differential diagnosis of a spine tumor (3)?
1) Low grade astrocytomas
2) Ependymomas
3) AA/GBM (much less commonly)
What is the differential diagnosis of a posterior fossa tumor (5)?
1) Pilocytic astrocytoma
2) Medulloblastoma
3) Ependymoma
4) ATRT
5) DIPG
How would you differentiate on imaging a brainstem diffuse midline glioma vs pilocytic astrocytoma?
DIPG (diffuse midline glioma H3K27M mutant): diffuse, commonly but not always in the pons, encasing basilar artery
PA: exophytic, bright post-gad, can occur anywhere in the brainsteam
Which brain tumors don’t need to be biopsied for Dx?
1) NG-GCT (if positive tumor markers)
2) Diffuse midline glioma H3K27M mutant, unless atypical features
Which brain tumors are usually not considered for radiation therapy?
1) Choroid plexus carcinoma
2) LGG, unless failure of other options
What is the common radiological appearance of pilocytic astrocytoma?
Most often cerebellar location (but can happen anywhere), contrast-enhancing, bright on T2, classically nodule with cyst
What targeted therapy could be considered if…
a) BRAF fusion
b) BRAF V600E mutation
a) MEK inhibitor e.g. trametinib
b) BRAF inhibitor
Staging: LGG and HGG
MRI of brain +/- spine
No metastatic potential outside the CNS
Prognosis of HGG
Anaplastic astrocytoma: 30% (GTR and adjuvant chemo)
GBM: EFS 18%
What is the OS for
a) Germinoma
b) NGGCT
a) Germinoma:
OS>90%
b) NGGCT
OS 70%
What is growing teratoma syndrome?
Syndrome associated with NGGCT(pathology invariably mature teratoma)
Rapid radiological enlargement with progressive decrease of tumor markers
Treatment: surgical resection, ideally gross total extirpation followed by RT
Germinoma: treatment
Localized:
Chemotherapy (carboplatin-etoposide, or ifosphamide-etoposide-carboplatin) followed by radiation (whole ventricular RT 24Gy with tumor boost 16Gy)
COG testing lower RT dose
In new trial
Metastatic:
Chemotherapy (carboplatin-etoposide, or ifosphamide-etoposide-carboplatin) followed by radiation (craniospinal RT with tumor boost)
Treatment: NGGCT
- Chemotherapy (platinum based, for example ifos-carbo-etoposide)
followed by - RT: volume and dose debated; COG does CSI at 36Gy with tumor boost
- Surgical excision for mature teratoma and benign immature teratoma
Epidemiology of GCT (CNS)
a) Histologic subtypes
b) Sex predominance
A) 60-70% Germinomas
30-40% NGGCT
b) Male prédominance in general
Pineal region: 15M:1F
Suprasellar region: slight female predominance
RF for brain tumors
- Ionizing radiation (meningioma, HGG, sarcoma)
- Immunosuppression (CNS lymphoma)
- Specific genetic conditions (differs for each brain tumors)
No proven environmental factor
Describe histologic features PA
- Rosenthal fibers
- Eosinophilic granular bodies
- GFAP (+)ve
- Low mitosis rate (MIB1 < 4%)
LGG: prognosis
OS: very good (>90%)
PFS: depends on the location; about 50% in unresectable lesions
Classical presentation of optic pathway glioma
- Visual loss
- Proptosis
- Optic nerve atrophy
Clinical course very variable, usually more indolent in NF1-OPG