title: Subcortical heterotopia appearing as huge midline mass in the newborn brain.
abstract: BACKGROUND
  We report the case of a 2-year-old boy who showed a huge midline mass in the brain at prenatal assessment.
  
  
  METHODS
  After birth, magnetic resonance imaging (MRI) revealed a conglomerate mass with an infolded microgyrus at the midline, which was suspected as a midline brain-in-brain malformation. MRI also showed incomplete cleavage of his frontal cortex and thalamus, consistent with lobar holoprosencephaly. The patient underwent an incisional biopsy of the mass on the second day of life. The mass consisted of normal central nervous tissue with gray and white matter, representing a heterotopic brain. The malformation was considered to be a subcortical heterotopia. With maturity, focal signal changes and decreased cerebral perfusion became clear on brain imaging, suggesting secondary glial degeneration. Coincident with these MRI abnormalities, the child developed psychomotor retardation and severe epilepsy focused on the side of the intracranial mass.
authors.affiliation: Department of Pediatrics, Sapporo Medical University School of Medicine, Chuo-ku, South-1, West-16, Sapporo, 060-8543, Japan. fukumura@sapmed.ac.jp.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Fukumura
authors.affiliation: Department of Child Neurology, Hokkaido Medical Center for Child Health and Rehabilitation, Sapporo, Japan.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Surgical Pathology, Hokkaido Medical Center for Child Health and Rehabilitation, Sapporo, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Department of Neurosurgery, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Ochi
authors.affiliation: Department of Neurosurgery, Hokkaido Medical Center for Child Health and Rehabilitation, Sapporo, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Yoshifuji
authors.affiliation: Department of Pediatrics, Sapporo Medical University School of Medicine, Chuo-ku, South-1, West-16, Sapporo, 060-8543, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsutsumi
mesh_terms: D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D002675:Child, Preschool; D002828:Choristoma / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D054221:Classical Lissencephalies and Subcortical Band Heterotopias / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D004569:Electroencephalography; D004827:Epilepsy / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D016142:Holoprosencephaly / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D011247:Pregnancy; D011596:Psychomotor Disorders / Q000209:etiology; D016216:Ultrasonography, Prenatal
keywords: Epilepsy; Histology; Holoprosencephaly; Midline brain-in-brain malformation; Subcortical heterotopia