Case Report CT and MRI Features of Pediatric-Aged Colloid Cysts: Report of Two Cases Hidayatullah Hamidi, Fazel Rahman Faizi, Najibullah Rasouly, and Mer Mahmood Shah Hoshang French Medical Institute for Children (FMIC), Kabul, Afghanistan Correspondence should be addressed to Hidayatullah Hamidi; hedayatullah.hamidi@gmail.com Received 24 September 2016; Revised 18 December 2016; Accepted 11 January 2017; Published 31 January 2017 Academic Editor: Alberto Spalice Copyright © 2017 Hidayatullah Hamidi et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A 10-year-old boy with the history of headache, anorexia, and vomiting was referred to our department to undergo a brain CT scan. CT images demonstrated a well-defned, rounded, hyperdense lesion at the level of the foramen of Monro causing moderate dilatation of the lateral ventricles. An 11-year-old girl with a long history of a headache was also referred to undergoing a brain MRI. MR images demonstrated a well-defned round abnormal signal intensity lesion at the level of the foramen of Monro causing moderate dilatation of lateral ventricles. Te fndings from imaging perspective were consistent with the colloid cyst of the third ventricle. Terefore, the diagnosis of the colloid cyst was made. 1. Introduction Colloid cysts are benign intracranial neoplasms constituting 1% of CNS tumors. Tey may be totally asymptomatic or may manifest with symptoms of raised intracranial pressure. Te symptoms may be intermittent, self-limiting, and non- specifcally apparent when the foramen of Monro is blocked temporarily by pendulous movement of the cyst or may be acute and severe presenting with acute hydrocephalus, brain herniation, and sudden death. Tey usually appear as hyperdense lesions on CT; however, they can manifest as isodense or hypodense lesions as well. Te appearance of the lesion on MRI is variable on diferent sequences and is dependent on cholesterol and protein contents of the cyst. 2. Case Presentation 2.1. Case 1. A 10-year-old boy with the history of headache, anorexia, and vomiting was referred to Radiology Depart- ment of French Medical Institute for Children to undergo a brain CT scan. Te CT scan was performed with 128 slices’ Siemens scanner. Precontrast images demonstrated a well-defned, rounded, hyperdense lesion at the level of the foramen of Monro causing moderate dilatation of the lateral ventricles. No specks of calcifcation were appreciated in the cyst. No signifcant enhancement appeared afer intravenous contrast injection (Figures 1(a) and 1(b)). 2.2. Case 2. Interestingly, an 11-year-old girl with a long history of headache was referred to undergoing a brain MRI. Te MRI was performed with 1.5 Tesla Siemens machine. A well-defned rounded abnormal signal intensity lesion was visualized at the foramen of Monro resulting in moderate acute hydrocephalus. Te lesion was isointense to gray matter on T2WI and hyperintense on T1WI and FLAIR images. No drop of the signal was visualized in T2 * GRE sequence to suggest intralesional hemorrhage. No difusion restriction was noted. Subtle enhancement of the lesion was seen on postcontrast images (Figures 2 and 3). Te frst case did not receive any surgical treatment and, afer ten months of follow-up, he claimed that the symptoms have diminished. Te second case was lost of follow-up. 3. Discussion Colloid cysts are benign congenital tumors of the brain located in the anterosuperior part of the third ventricle comprising 1% of CNS tumors and occur in three individuals Hindawi Publishing Corporation Case Reports in Radiology Volume 2017, Article ID 2467085, 4 pages http://dx.doi.org/10.1155/2017/2467085