title: Tumors of the superior medullary velum in infancy and childhood: report of 6 cases.
abstract: OBJECTIVE
  The superior medullary velum (SMV) is a thin lamina of white matter located between the superior cerebellar peduncles horizontally and between the midbrain and cerebellum vertically. The SMV has not previously been described as the primary location of a posterior fossa tumor, although it can be secondarily invaded by a tumor from the cerebellum or quadrigeminal plate. This paper aims to define clinical and radiological features of tumors primarily arising from the SMV during childhood.
  
  
  METHODS
  The authors observed 6 infants and children harboring neoplasms of the SMV who were treated at Ann & Robert Lurie Children's Hospital of Chicago (formerly Children's Memorial Hospital) in Chicago, Illinois. Pathological diagnosis of the neoplasms was an atypical teratoid/rhabdoid tumor (ATRT) in 5 patients, and a juvenile pilocytic astrocytoma (JPA) in the remaining child. The tumors were diagnosed during infancy in all patients, with ages ranging from 3 months to 10 months, except for the patient with a JPA (diagnosed at 5 years old). All patients presented with signs and symptoms of increased intracranial pressure due to obstructive hydrocephalus.
  
  
  RESULTS
  Characteristic MRI features were noted, consistent with a mass in both the fourth ventricle and the cerebellomesencephalic fissure and quadrigeminal cistern, resulting in the circumferential displacement of the neural structures surrounding the SMV. The tumor was removed effectively in gross-total fashion through the occipital transtentorial approach in all patients. This approach offers a wide exposure of the region. However, all infants with ATRT suffered tumor dissemination and died between 4 and 11 months after diagnosis, in spite of radical resection and oncological treatment. The 1 child with JPA is alive and well 30 months after tumor resection.
  
  
  CONCLUSIONS
  To the best of the authors' knowledge, this is the first description in the literature that focuses on tumors originating from the SMV. This entity must be promptly recognized on preoperative radiological studies to carefully plan the subsequent surgical and clinical management.
authors.affiliation: Division of Pediatric Neurosurgery, Ann & Robert Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA. ttomita@childrensmemorial.org
authors.forename: Tadanori
authors.initials: T
authors.lastname: Tomita
authors.forename: Paolo
authors.initials: P
authors.lastname: Frassanito
mesh_terms: D000970:Antineoplastic Agents; D020295:Brain Stem Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy; D002551:Cerebral Ventricle Neoplasms / Q000473:pathology; D002552:Cerebral Ventricles / Q000473:pathology; D002675:Child, Preschool; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics; D003131:Combined Modality Therapy; D003399:Craniotomy / Q000379:methods; D004268:DNA-Binding Proteins / Q000235:genetics; D017809:Fatal Outcome; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D019635:Neurosurgical Procedures; D000071796:SMARCB1 Protein; D014057:Tomography, X-Ray Computed; D014157:Transcription Factors / Q000235:genetics; D016896:Treatment Outcome; D017287:Ventriculoperitoneal Shunt
chemical_list: D000970:Antineoplastic Agents; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D000071796:SMARCB1 Protein; C513266:SMARCB1 protein, human; D014157:Transcription Factors