1. COLLOID CYST OF THE 3RD VENTRICLE
AHMED ADEL, M.Sc, MRCSI, CG-FNE, FEBNS, M.D

2. OVERVIEW

3. EPIDEMIOLOGY
• About 0.5–1% of all intracranial tumors.
• Usual age of diagnosis: 20–50 yrs.
• Children ????????
• Most commonly found in the third ventricle in the region of the
foramina of Monro, but may be seen elsewhere, e.g. in septum
pellucidum.

4. PATHOLOGY
Pathogenesis origin: unknown, abnormal folding of the primitive
neuroepithelium (the paraphysis elements)
Pathology: Comprised of a fibrous epithelial-lined wall filled with
either mucoid or dense hyloid substance, occationally old blood
(hemosiderin).
Microscopic: These cysts are lined by a single layer of columnar
epithelium which produces mucin

5. CLINICAL PRESENTATION:
•“Asymptomatic” > 50 % incidental.
•Headache is the most common presentation.
•Patients may start to have headaches once diagnosed.
•Careful evaluation of headache aetiology.
•Non specific presentation.
•Memory affection> subclin.

7. MOCA TEST: PRE AND POSTOP

8. NATURAL HISTORY

11. Kamc female 84 yrs (2 yrs fu)
august 2020

12. July 2021

13. 1 March 2022
8 march

16. Risk of Acute Deterioration 34% in Symptomatic Colloid Cyst

18. • 163 colloid cysts,
• more 50% were discovered incidentally.
• 8.8% progressed and underwent resection (FU 5yrs).
• In another study 8% in 10 yrs.
• No patient with an incidental, asymptomatic colloid cyst
experienced acute obstructive hydrocephalus or sudden
neurological deterioration in the absence of antecedent trauma.
• 46.2% of symptomatic patients presented with hydrocephalus.
• 12.3% presented acutely.
• About 3 % risk of death of the symptomatic group.

20. A CCRS ≥ 4 was significantly associated
with obstructive hydrocephalus

21. Female pt 51 yrs old , 5yrs compensation

22. SUDDEN DEATH

24. • Ranges from 3% to 5% of patients.
• MECHANISM:
• Colloid cysts are mobile and thus could shift position and acutely
block CSF flow with resultant herniation.
• Progressive obstruction from tumor growth does often produce
chronic hydrocephalus, and it is possible that at some point the
brain may decompensate in some cases.
• Changes in CSF dynamics resulting from procedures (LP,
ventriculography, trauma) may have also contributed.
• Disturbance of hypothalamic-mediated cardiovascular reflex
control.
• CYST APOPLEXY.

25. Don’t …until you do….

26. Radiology

27. Radiologically
• MRI: usually the optimal imaging technique. However, there are cases
where cysts are isointense on MRI and CT is superior
• MRI appearance: variable. Usually hyperintense on T1WI,
hypointense on T2WI. Some data suggests that symptomatic patients
are more likely to display T2 hyperintense cysts on MRI, indicating
higher water content which may reflect a propensity for continued
cyst expansion.
• Enhancement: minimal, sometimes involving only capsule.
• CT scan: findings are variable. Most are hyperdense (however, iso-
and hypodense colloid cysts occur), and about half enhance slightly.
Density may correlate with viscosity of contents; hyperdense cysts
were harder to drain percutaneously.
• These tumors rarely calcify.

28. CT

29. Size

30. Giant > 5cm

31. MRI

32. MRI Signal Correlation With The Content

35. DDX

37. Rare DDX: It is a spot dx
• Basilar artery aneurysms
• Calcified meningioma
• Blood in the region of the FM
• Neurocysticercosis
• Hamartomas
• Primary or secondary neoplasm
• Xanthogranulomas
• Pilocytic astrocytoma

38. DON’T FORGET
•T2 BLACK HOLE SIGN
•T2 HYPERINTENSITY
•FLAIR HYPERINTENSITY
•HGIC COLLOID CYST

39. Management

40. •OBSERVATION
•SHUNTING
•SURGICAL RESECTION
Shunt dependency.
Tumor progression>> compress
Hypothalamus.
Symptomatic progression in
asymptomatic cysts 8% in
10 years

44. `

45. 5-10%
2.7%

46. CHOICE BETWEEN TRANSCORTICAL OR TRANSCALLOSAL
• Degree of dilatation of the lateral ventricles.
• Venous anatomy of the frontal cortex.
• Thickness of cortical mantle.
• Specific location and extent of the colloid cyst in the third ventricle.
• Patient presentation (Acutely decompensated) and preoperative
cognitive function.

47. Which approach is the best?

52. VENTRICULOSCOPIC RESECTION

54. THE BEST OUTCOME = LOW MORBIDITY + GTR

55. GOOD OUTCOME REQUIRE:
• PROPER PT SELECTION
• SUITABLE EQUIPMENT
• GOOD PLANNING OF ENTRY POINT
• BIMANUAL TECHNIQUE
• SHARP DISSECTION AVOID MUCH PULLING
• RETRACTION WITH ENDOSCOPIC TROCAR
• PROPER HAEMOSTASIS
• SCIT
• DRY FIELD TECHNIQUE

56. PROPER PT SELECTION

58. SUITABLE EQUIPMENT

61. Always be ready

62. PLANNING OF ENTRY POINT

67. BIMANUAL TECHNIQUE

69. RETRACTION WITH ENDOSCOPIC SHEATH

71. HAEMOSTASIS

73. SCIT

74. SCIT

76. MULTIFUNCTIONAL SUCTION CANNULA

79. CASES

80. CASE 1

82. Case # 2: T2 black dot sign

84. Case # 3: Small FM

86. Case # 4

87. Case # 5:

89. Case 6

91. Case #7: Subchoriodal approach

92. Case # 8:

93. Case 9: male pt 29 yrs endoscopic 2019

94. Residual 2020

95. 2021

96. 2022

98. Case # 10:

100. Pt Headache did not improve

101. Meticulous studying of the MRI image is important to
choose the proper approach.
 Proper pt selection and skillful endoscopic techniques can
help to achieve GTR WITHOUT complication.
Always be ready for any intraop. event.
Don’t be forced by the pt to do unnecessary surgery.
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102. BEFORE WE END