Brain tumours

General Basic knowledge of Brain tumour explained in brief of classification, pathogenesis, clinical features, CT, MRI, management, Radiotherapy. Best for MBBS and PG preparation student.

1. Brain Tumours Dr. Fakir Mohan Sahu SR MCh Neurosurgery Dept of Neurosurgery AIIMS Bhubaneswar

2. Learning Objectives Epidemiology and incidence Anatomical consideration and location Classification of brain tumours Clinical features Diagnostic imaging Individuals tumours Treatment modalities Recent Advances

3. Introduction A wide variety of tumors affect the CNS (Brain + Spinal cord) Primary benign and malignant tumors arise from the various elements of the CNS, including neurons, glia, and meninges. Tumors metastasize to the CNS from many primary sources. Presentation varies widely depending on relevant neuroanatomy. Prognosis depends on histology and anatomy Team approaches to CNS tumors, as patients may require a combination: Surgery, Radiation Therapy Chemotherapy and Research Protocol Enrolment.

4. Epidemiology of Intracranial tumour In general, primary brain tumors is higher in whites than in blacks Males are more likely to be diagnosed with brain tumors than females-( 1.5:1 ) Meningiomas and pituitary adenomas are slightly more common in women than in men. Mortality is higher in males than in females. Brain tumours are responsible for 2% of all cancer deaths. The incidence varies with age. In children CNS tumours comprise 20 % of all childhood malignancies. P eak at 2 years followed by a decline for the rest of the first decade. The incidence then slowly increases, peaking at 20 per 100 000 in late adulthood.

5. Anatomic consideration and location of tumours The brain consists of The Cerebrum - 2 Large Cerebral Hemisphere 4 major lobes The Cerebellum Brainstem Midbrain Pons Medulla

6. Location In adults supratentorial tumours out number posterior fossa tumour by a ratio of 7 to 3 But in children this ratio is reversed and posterior Fossa tumours are the most common .

7. Classifications Intracranial tumour can be classified in different ways: Paediatric versus adult, by cell of origin B y location in the nervous system.(Supratentorial/ Infratentorial/ Intraventricular) Classification of brain tumour (according to cell of origin) Neuroepithelial tumours 50% M etastatic 15% Meningioma 15% Pituitary tumour 8% Others

8. Primary Tumour Primary intracranial tumour can occur at any age, it is helpful in deferential diagnosis to know that certain tumor occur mainly in certain age groups. B R A I N T U M O UR Secondary Tumour These affect mainly the middle aged and elderly, with the exception of secondary neuroblastoma which occurs mainly in children . Classification

9. C LASSIFICATION OF INTRA CRANIAL TUMOURS: There are several ways of classifying brain tumours: primary versus secondary intraxial ( arising from the brain parenchyma) versus extra axial ( arising from tissue covering the brain such as dura) and various regional classification Supratentorial Infratentorial Intraventricular Pineal region Sellar region tumours. Contd ..

10. Astrocytomas Oligodendroglioma Ependymal tumours CLASSIFICATION ACCORDING TO HISTOLOGY Primary brain tumours are subdivided into two basic groups: Tumours of neuroglial origin ( Glioma) Non - glial tumours that are specified by a combination of putative cell origin and specific location. Glial tumors ( gliomas) Contd ..

11. N O N G L I A L TU M OU R S Neuronal and mixed neuronal- glial tumours Ganglioglioma G a n g li o cy t om a Meningeal and mesenchymal tumours Meningioma H e m a n g i o p e r i cy t om a Hemangioblastoma Fibrous histiocytoma Contd . .

12. N ONG L I A L T U MO U R S Pineal region tumours Pineocytoma Pineoblastoma Pineal cell tumours C ho r i o c a r c i n o m a Teratoma Germinoma Germ cell tumours Contd ..

13. Nonglial tumours Other cell tumours Benign pineal cysts Astrocytoma Embryonal tumours N e u ro b l a s t om a Primitive neuroectodermal tumours ( PNET) Cranial and spinal nerve tumours Schwannoma N e u ro f ibrom a

14. NONGLIAL TUMOURS H e mop o e ti c neoplasm's Lymphoma Leukemia P l a s m a c y t o m a Pituitary tumours Contd ..

15. NO N G L I A L TU M OU R S Cysts and tumour like lesions Rathke cleft cyst Dermoid cyst Epidermoid cyst Colloid cyst Enterogenous cyst Neuroglial cyst Lipoma H a m a r t om a Contd . .

16. NO N G L I A L TU M OU R S C o n t d . Local extensions from regional tumours C r a niop h a r y n g i o m a Paraganglioma Chordoma According to location Intra axial Extra axial

17. P o i n t s Intra axial Extra axial Within brain p a r e n c h y m a . Outside brain parenchyma Y e s Location Contiguity with bone / flax Bony changes CSF space Usually not Usually not Effaced Yes Often widened Corticomedullary buckling N o Y e s GM / WM junction Destruction Vascular supply Internal carotid artery Preservation External carotid artery

18. S u pr a t e n t o r i a l Meningeoma Dermoid Epidermoid Pitutary adenoma Pineal region tumour Craniopharyngeoma Chordoma

19. Infratentoria l Brainstem glioma Cerebellar astrocytoma Medulloblastoma Ependymoma Meningioma Hemangioblastoma Dermoid Acoustic neuroma Meningioma Dermoid Chordoma Glomus jugular tumour

20. OTHER C L A SSIF I C A TI O N Intraventricular tumour Ependymoma Choroid pluxus tumor Colloid cysts M e ning i o m a

21. C L A SS I FI C A T I O N – A CC O R DI N G A G E GROUP 5 - 1 5 YEARS CLASSIFICATION 0-5 Brain Stem Glioma, Optic Nerve Glioma Medulloblastoma, Cerebellar Astrocytoma, Craniopharyngma, Choroid Plexus Papiloma , Pinealoma. 1 5 - 3 3 - 6 6 + Ependymoma Glioma, Meningioma, Acoustic neuroma, Pitutary Tumour, Hemangioblastoma Meningeoma, Acoustic Neuroma, Glioblastoma

22. W H O C L A S S I F I C A T I O N CLASSIFICATION Pilocytic astrocytoma SGCA( subependymal giant cell astrocytoma) Low grade astrocytoma Anaplastic astrocytoma GRADE Grade 1 Grade 2 Grade 3 Grade 4 Glioblastoma multiforme

23. FE A TU R E S O F L O W G R A D E GLIOMA Age – Younger age group 20- 40 yrs Incidence – 10- 20% of astrocytoma Location – Histology- cerebral hemisphere frontal and parietel lobe temporal lobe low grade malignancy Presenting Symptom - Seizure

24. I M A GI N G S T UD Y L O W G R A D E G L I O M A C T NECT : Iso/hypo CECT : Little or no enhancement

25. I M A G IN G S T UD Y L O W G R A D E G L IO M A MRI T1 : Iso/Hypointense T2 : Homogenously hyper

26. ANAPLASTIC ASTROCYTOMA It usually occurs in the middle aged patients Incidence- 20- 25% Locations: cerebral hemispheres frontal and temporal lobe Histology- malignant Presenting Symptom- Seizure, focal neurological deficit

27. C T I M A G IN G S T UD Y A N A P L A S T I C A S T R O C Y TO M A NECT : Iso/hypo In homogenous mixed density CECT : Enhance strongly, inhomogenously

28. IMAGING STUDY ANAPLASTIC ASTROCYTOMA MR I T1: Hypo to iso intense T2 : Heterogenously Hyperintense As typically enhance strongly but non uniformly following contrast administration. Irregular rim enhancement is common

29. GLIOBLASTOMA MULTIFORME Half of all astrocytoma are GBM. It is most common supratentorial neoplasm in adult. The most common primary brain tumour, it is also the most malignant astrocytoma Incidence – Age- Locations- Presenting symptom- d e f i c i t , 40-50%. 50yrs. cerebral hemisphere, Frontal and temporal lobe, White mater Seizure, Focal neurological stroke like syndroms

30. I M A GI N G S T U D Y Enhances strongly, inhomogenously. Ring enhancing lesion – due to increased cellularity and neovascularity. Area of central necrosis shows hypodensity Imaging study shows ‘multiforme’ appearance CT N ECT : In homogenously mixed density

31. MRI T1: T1 weighted image shows mixed signal mass with necrosis or cyst formation and thick irregular wall. Marked but in homogenous contrast enhancement is present in majority of glioblastoma multiforme. These tumours are hihgly vascular, haemorrhage of different ages are often present. T - 1 T-1 C T-1 C

32. MRI T2: T2- weighted image shows very heterogenous mass with mixed signal intensity. Central necrosis is the hall mark. Haemorrhage , necrosis, oedema are present in GBM A n g i o g r a p h y A large mass with striking tumours blush, Contrast stasis and pooling in Bizarre vascular channel is typical

33. IMAGING STUDY Contd. S p r ea d Through white mater Sub ependymal seedling Through CSF Rarely through haemtogenous route Extra cerebral metastasis- Lung, Liver, Bone

34. MRI Sharply defined macrocystic mass Mural nodule easily appreciate with contrast enhancement PILOCYTIC ASTROCYTOMA IMAGING STUDY

35. OLIGODENDROGLIOMA Arise from a specific type of glial cell- Oligodendrocyte. These are typically unencapsulated but well circumscribed focal white matter tumours that may extent into the cortex and leptomeninges. Foci of cystic degeneration common Hge, necrosis uncommon I n c i d e n c e - Age distribution- Peak age Location - - 5- 10% of gliomas 4th to 5th decade 35- 45 yrs. 85% supratentorial Cerebral hemisphere- mostly frontal lobe

36. IMAGING STUDY- O L I G O D E ND RO G L IO M A CT NECT - Prominent mass of calcification. Partially calcified mixed density hemispheric mass that extends peripherally to the cortex. CECT - Mild to moderate contrast enhancement occurs

37. MRI Heterogenous signal intensity due to calcifiacation T1W ii m age shows mixed hypo or iso intensity T2 W image shows hyper intense foci Absent to slight enhancement is typical T- 1 T- 1 C T - 2 IMAGING STUDY- O L I GO D E NDR OG L I O M A

38. EPENDYMOMA Ependymomas are tumours of the young and are third most common intracranial tumour of children Age distribution- Incidence- 1-5 yrs. 2-8% of gliomas 15% of pediatric brain tumour Location- 60% infratentorial more common in children . 40% supratentorial more common in adult . 4th ventricle, C- P angle, in or near 3rd ventricle

39. IMAGING STUDY- EPENDYMOMA CT N E CT - C E CT - Mixed density, isodense or slightly hyperdense Fine calcification seen in approximately 50% of the patients. May have cystic areas More than 80% contrast enhancement occurs

40. MRI T 1 - Heterogenous signal intensity markedly hypointense area due to calcification In homogenous enhancement with gadolinium T 2- Iso to hyper intensity Histological feature shows uniform ependymal cells in pattern of rosettes, canal or perivascular pseudorosettes

41. CHOROID PLEXUS PAPILLOMA Tumours of choroid plexus are rare, accounting for 0.4- 0.6% of all intracranial tumour Age distribution- > 85% occurs in children L o c a ti o n In children MC site lateral ventricle In adult most of the choroid plexus papilloma occurs in 4th ventricle

42. I M A G I N G S T U D Y C H O R OI D P L EX U S PAPILLOMA CT N E C T C E C T Iso or hyperdense, 3/4th hyperdense heterogenous contrast enhancement

43. MRI T1 weighted image shows- Predominently isointense Intensely contrast enhancement occurs T2 weighted image shows- Iso to hyperintense, occasionally signal void from the vascular pedicle I M A G IN G S T UD Y CH O R O I D P L EX U S PAPILLOMA

44. P I N E A L T U M OU R , C on t the incidence of The pineal region tumours are rare tumour which is 1% of all intra cranial tumour. Gemcell tumour Pineal cell tumour G e r m inom a Teratoma Embryonal carcinoma Choriocarcinoma P i n e a l o b l a s t o m a Pinealocytoma Types of pineal region tumour are as follows

45. SELLAR/SUPRASELLAR MASSES The sellar region is an anatomically complex area composed of the bony sellaturcica, pituitary gland, and adjacent structures Pituitary adenoma Older classification C h romop h o b i c Acido philic Basophilic Mixed New classification Pituitary microadenoma ( size < 10mm) Pituitary macroadenoma ( size

46. I M A G I N G ST U D Y X- ray expansion of sellar cavity thining of bony cortex ballooning of sella CT Large, homogenously isodense, rounded midline mass

47. M R I T 1 weighted image shows hypointense T 2 weighted image shows hyperintensity Extension is better visualized after contrast Both CT and MRI show strong contrast enhancement with some what inhomogenously

48. M E N I N G E A L A N D M ESE NCH Y M A L T U M O U R Meningiomas Malignant mesenchymal tumour Hemangiopericytoma Hemangioblastoma Meningiomas Meningiomas are most common nonglial primary brain tumour Most common extra axial tumour ( 13- 18%) Age – adult tumour 40- 60yrs Sex- more in female Cytogenetics- chromosome 22 is important for pathogenesis of meningioma

49. Location meningioma Cerebral convexity 32- 45 % P a r a s a g it a l 26 % Sphenoid ridge Juxtra sellar 20 % 10 % olfactory groove 10 % Posterior fossa 10 % Tentorium Pineal region O t h e r s optic nerve sheath, intravetrricular

50. I M A G E ST U D Y X- ray H y p e r o s t o s i s Erosion Enlarged vascular Calcification Pneumosinus dilatans

51. I M A G E S T UD Y CT 70% to 75% hyperdense 20% to 25% calcified 90% enhance strongly , uniformly 10% to 15% cystic areas 60% peritumoral edema H e m o r r h a g e rare Area of haemorrhage, necrosis, cyst formation are c o m mo n which appear as hypodense within the tumour

52. I M A G E ST U D Y Angiography Dual vascular supply common Sunburst of enlarged dural feeders in tumour Extension Into the suprasellar cystern forming the figure of eight( 8 ) Elevate and compress the optic chiasma and 3rd ventricle Laterally into the cavernous sinus May encase the ICA or narrow the vessels

53. Common CPA masses Vestubular schwannoma ( acoustic neuroma) Meningioma Epidermoid Other schwannoma Less com . Arachnoid cyst Metastases Vascular Lipoma Dermoid. CEREBELLOPONTINE ANGLE ( CPA) CISTERN MASSES

54. MEDULLOBLASTOMA Most common malignant pediatric brain tumour. Incidence: 15- 20% of intracranial tumour in children. Male: Female 2:1. Age: most in 1st decade. 75% in 4- 8 years. Site: 75% arises in the cerebellar vermis mostly in midline, in the apex of 4th ventricle. 25% arises in lateral cerebellum. Highly radiosensitive and moderately chemo sensitive. Metastasis occur early in the CSF. Prognosis is very poor

55. CRANIOPHARYNGIOMA Craniopharyngiomas arise from the squamous epithelial rests along the involuted hypophyseal Rathke’s duct. Incidence: 3- 5% of primary brain tumour. 50% of pediatric brain tumour. Age: > 50% in children, peak between 8-12 years. Location: 70 % combined suprasellar and intrasellar Imaging study CT scan of brain- 90% partially cystic, 90% calcification present, 90% nodular or rim enhancement occur MRI of Brain Variable signal, most common is hypointense in T 1 weighted image and hyperintense in T2 weighted image

56. INTRACRANIAL METASTASES Representing 1/ 4th to 1/ 3rd of all brain tumour. Common: Skull Leptomeninges Parenchymal (most common). Less common: D u r a l Pial Sub pial Parenchymal metastases: Location – any where but most common in cortico medullary junction ( grey mater- white mater interface).

57. INTRACRANIAL METASTASES Pathology Welldefined circumscribed nodule of variable size May be solid partially cystic, filled with mucinous material, necrotic material, haemorrhagic fluid . Imaging Study CT: NECT- mostly isodense lesion / hyperdense lesion- Example- Thyroid carcinoma, Lung carcinoma, choriocarcinoma, malignant melanoma, sarcoma

58. INTRACRANIAL METASTASES Cystic metastasis Mucin producing tumour adenocarcinoma arising from stomach, small and large intestine, pancreas, ovary, breast cancer Cystic and calcified metastasis Rare- breast carcinoma, lung cancer. CECT: Most enhance strongly, both solid and ring shaped pattern are noted MRI T 1 weighted image- shows variable features most non haemorrhagic tumour slightly hyper intense. Some non haemorrhagic tumour – hyper intense

59. General Consideration

60. Surgical management: Craniotomy + Excision  Approaches Craniotomy:- flap of bone is cut and reflected. If necessary, combined with either a stereotactic frame or preferably an image guided system(frameless, steriotaxy) to give accurate lesion localisation

61. Operative procedure: The subsequent procedure Biopsy Partial tumour removal Internal decompression C omplete removal Depends on the nature of the tumour & site. Primary malignant tumour : complete removal of tumour is not possible due to its infiltrative nature. So operation is restricted to - biopsy - Tumour decompression Complete removal is done for Meningioma Craniopharyngioma

62. Radiotherapy Aim : to provide highest possible dose to the specific region, while minimal irradiation to adjacent normal brain. Indication: In malignant tumour: malignant astrocytoma metastasis medulloblastoma germinoma In benign tumours pituitary adenoma craniopharyngioma

63.  Malignant astrocytoma: -nitrosoureas are most effective drug commonly used treatment for relapse patient  Low grade tumour or benign tumour : chemotherapy has limited value  Medulloblastoma: respond to treatment but value of treatment of patient survival – is unclear.  Primary germ cell tumour & primary cerebral lymphoma: chemotherapy has a role. Chemotherapy

64. Prognostics Variables For each tumour entity, combinations of parameters WHO grade Clinical findings- age/ neurologic performance Status Tumour location Radiological features - contrast enhancement Extent of surgical resection Proliferation indices Genetic alterations

65. Recent advances Neuro-navigation Stereotactic surgery Endovascular embolization Endoscopic Surgery

66. Thank You