LO: CNS Tumours

Question 1

What tumours commonly metastasize to brain?

Answer 1

Tumour (%of them that metastasize to brain):
Lung (44%)
Breast (10%)
Kidney (renal cell carcinoma) (7%)
GI (6%)
Melanoma (3%)

Question 2

What is the most common intra-cranial tumour in adults?

Answer 2

Metastasis: ~50% of all brain tumours

Question 3

What percentage of patients with cancer will have brain mets?

Answer 3

~25%

Question 4

Ix for metastatic brain tumour

Answer 4

• ID primary tumour
• CT with contrast
• contrast-enhancing MRI more sensitive, esp posterior fossa
• if no primary tumour IDed: consider biopsy

Question 5

CT signs of metastatic tumour

Answer 5

-Round, well-circumscribed, often ring enhancing. ++ edema. Often multiple.

Question 6

What is the prognosis with metastatic brain tumour(s)?

Answer 6

Median survival w/o treatment once symptomatic: 1mo; with optimal treatment, 6-9mo. Depends on tumour burden and primary tumour type. (Disease-specific Graded Prognostic Assessment useful.)

Question 7

DDx for ring-enhancing lesion on CT with contrast

Answer 7

MAGICAL DR R:
Metastasis
Abscess
Glioblastoma
Infarct
Contusion
AIDS (toxoplasmosis)
Lymphoma
Demyelination
Resolving hematoma
Radiation Necrosis

(first 3 are most common)