RT Journal Article SR Electronic T1 Holoprosencephaly or severe hydrocephalus: T1 sequence tells the story JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e228648 DO 10.1136/bcr-2018-228648 VO 12 IS 5 A1 Fariba Zarei A1 Pooya Iranpour A1 Sara Haseli YR 2019 UL http://casereports.bmj.com/content/12/5/e228648.abstract AB Intracranial lipoma is a relatively rare benign lesion. Many are incidental findings; however, some others may present with headache, hydrocephalus or other neurological symptoms; thus, correct diagnosis of this condition is important. These lesions are of high signal intensity on T2-weighted MRI and especially those close to cerebrospinal fluid (CSF) spaces, can easily be overlooked in the background of high signal intensity of CSF. Here, we present a case of tectal lipoma, with subsequent severe hydrocephalus and absence of septum pellucidum which was initially misinterpreted as a form of holoprosencephaly, due to inadequate attention to T1-weighted images.