Brain Neoplasms: Pathogenesis and clinical findings
Authors: Steven Chen, *Yan Yu Reviewers: Calvin Howard, Heather Yong, Tony Gu, *Scott Jarvis * MD at time of publication
Metastatic Lesions
(e.g., primary tumour from breast, lung, gastrointestinal, prostate)
Mutagen exposure (e.g., radiation, carcinogens)
Errors of DNA replication
Acquired cell mutations leading to uncontrolled cell division in the brain
Inherited diseases (e.g., neurofibromatosis, tuberous sclerosis)
Primary Brain Tumours
(e.g., gliomas, meningiomas, pituitary adenomas)
Brain Neoplasms
Tumors in the brain arising from brain tissue itself (primary) or from non-brain tissue (metastatic)
Tumor produces vascular endothelial growth factor (VEGF) which generates new vessels (angiogenesis)
Tumor occupies intracranial space
↑Intracranial pressure
Tumor irritates grey matter
Seizures
Headaches Papilledema
Tumor outgrows and disrupts its blood supply
Cerebral ischemia and/or necrosis
Critically located tumors may damage specific neural pathways
Tumor invades, infiltrates, or replaces normal brain parenchyma
Friable blood vessels within tumor àeasy bleeding
Brain hemorrhage
Disrupted blood- brain barrier
↓ blood vessel integrity à ↑ serum leaks out
Edema
Injury to localized brain regions; symptoms vary depending on location of brain affected:
↑ penetration of substances
(e.g., drugs, toxins)
Mass pressing on surrounding structures (mass effect on brain)
Frontal lobe damage
Personality change
Cerebellar damage
Ataxia
Occipital lobe damage
Visual deficits
If adjacent to 3rd/4th ventricles,
tumor will impede flow of cerebrospinal fluid
Obstructive Hydrocephalus
Stretching of meninges; activation of mechanoreceptors affecting the chemoreceptor trigger zone
Vomiting Nausea
Brain tissue pushed down beyond the
tentorium cerebelli, squeezing on brain stem
Brain Herniation
Note: Clinical findings tend to be similar for primary brain tumors and intracranial metastases.
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published February 17, 2020 on www.thecalgaryguide.com