Radiological Category Neuroradiology Principal Modality 1 CT Principal

Radiological Category: Neuroradiology Principal Modality (1): CT Principal Modality (2): MR Case Report # 797 Submitted by: Santosh Shah, MD Faculty reviewer: Scott Serlin, M. D. , the University of Texas Medical School at Houston Date accepted: 15 March, 2011

Case History 27 year old male with 3 year history of intermittent headaches presenting to the emergency room with 3 day history of increasingly severe headaches and blurry vision.

Radiological Presentations CT

Radiological Presentations CT

Radiological Presentations CT

Radiological Presentations T 1 + C

Radiological Presentations T 2 FLAIR

Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Colloid Cyst • Neurocysticerosis of the third ventricle • Ectopic craniopharyngioma • Prominent massa intermedia • Choroid plexus papilloma of the third ventricle • Choroid glioma • Vertebrobasilar doilicoectasia • Xanthogranuloma of the third ventricular choroid plexus

Findings and Differentials Findings: Colloid cyst within the anterior third ventricle obstructing the foramen of Monroe resulting in obstructive hydrocephalus. Differentials: • No other main differential considerations

Discussion: Colloid Cyst § Results from ectopic endodermal elements which migrate into the velum interpositum during neural development. § Contents accumulate mucinous secretions and enlarge overtime. § Equal male to female incidence. Usually presents in 3 -4 th decade. § 50% of patients are asymptomatic, symptomatic patients complain of headache, nausea, vomiting, altered personality, gait disturbance, visual changes § 10% of patients may present with hydrocephalus from obstruction of the Foramen of Monroe. Prompt decompression is necessary as herniation and death ensue from acute obstructive hydrocephalus. § Most common treatment includes complete surgical excision § Recurrence is rare if resection is complete

Discussion: Colloid Cyst CT § § Density correlates inversely with hydration state. 2/3 are hyperdense, 1/3 are isodense or hypodense Rarely calcified Usually do not enhance, however minimal rim enhancement may be present MR: § T 1: 2/3 are hyperintense, 1/3 are isointense § T 2: 75% are isointense to brain parenchyma, 25% show mixed hypo and hyperintensity § DWI: no restriction of diffusion § T 1 with contrast: usually do not show enhancement, but minimal rim enhancement can be seen § FLAIR: no suppression § MRS: no specific finding

Diagnosis Third ventricular colloid cyst resulting in obstructive hydrocephalus.

References 1. statdx. com 2. Armao D, Castillo M, Chen H, Kwock L. Colloid cyst of the third ventricle: imagingpathologic correlation. AJNR Am J Neuroradiol. 2000 Sep; 21(8): 1470 -7. 3. Jeffree RL, Besser M. Colloid cyst of the third ventricle: a clinical review of 39 cases. J Clin Neurosci. 2001 Jul; 8(4): 328 -31. 4. Osborn AG, Preece MT. Intracranial Cysts: Radiologic-Pathologic Correlation and Imaging Approach. June 2006 Radiology, 239, 650 -664. 5. Pollock BE, Schreiner SA, Huston J 3 rd. A theory on the natural history of colloid cysts of the third ventricle. Neurosurgery. 2000 May; 46(5): 1077 -81; discussion 1081 -3.