Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Images in Pediatric Neurosurgery Pediatr Neurosurg 2007;43:442–443 DOI: 10.1159/000106401 Giant Colloid Cyst in a Child Manish K. Kasliwal Sai Kiran Deepak Agrawal Bhawani Shankar Sharma Department of Neurosurgery, Neurosciences Center, All India Institute of Medical Sciences, New Delhi, India Key Words Colloid cyst  Pediatric intracranial neoplasm  MRI Abstract We describe a case of a giant third ventricular colloid cyst oc- curring in a 10-year-old child with unusual imaging features and discuss the causes for these imaging findings. Copyright © 2007 S. Karger AG, Basel Case Report A 10-year-old male child presented with complaints of episod- ic headache and vomiting. Visual acuity (Snellens) was 6/9 with bilateral papilledema on fundus examination. Remainder of the neurological examination and was normal. Biochemical investiga- tions including pituitary hormone profile were normal. CT (fig. 1) and MRI of the head showed a large (6.4 cm in the maximum di- ameter) well-defined nonenhancing lesion in the third ventricle, hyperintense on both T 1 - and T 2 -weighted images (fig. 2, 3). In view of the age of the child and MR features, intraventricular cra- niopharyngioma was considered more likely compared to a colloid cyst. A right frontal flap craniotomy with an anterior transcallosal approach was used to remove the cyst. Intraoperatively, the fora- men of Monro was found dilated and there was a cystic mass aris- ing from the roof of the third ventricle and extending into the lateral ventricle. The cyst was filled with hemorrhagic fluid with some areas of soft nodular growth inside. The cyst was totally de- compressed with excision of the wall. Histopathological examina- tion confirmed the diagnosis of colloid cyst. The patient had an uneventful postoperative course and is under follow-up. Received: November 30, 2005 Accepted after revision: July 19, 2006 Dr. Deepak Agrawal Department of Neurosurgery, Neurosciences Center All India Institute of Medical Sciences New Delhi 110029 (India) Tel. +91 986 810 3502, Fax +91 112 658 9650, E-Mail ved@vsnl.com © 2007 S. Karger AG, Basel 1016–2291/07/0435–0442$23.50/0 Accessible online at: www.karger.com/pne Fig. 1. Axial contrast-enhanced CT of the head showing the cyst to be isodense to brain and not enhancing on contrast. Fig. 2. Axial T 2 -weighted MRI showing a well-defined hyperin- tense lesion in the third ventricle with hydrocephalus. 1 2