title: Fourth ventricle neurocytoma with lipomatous and ependymal differentiation.
abstract: We report the case of a 4-year-old girl with a fourth ventricle tumor diagnosed as a cerebellar liponeurocytoma which recurred, showing ependymal differentiation, 14 months after surgery. Magnetic resonance imaging at initial presentation revealed a large mass in the fourth ventricle, and histology showed a neoplasm characterized by a combination of well-differentiated neurocytes and cells resembling adipocytes. The tumor recurrence was histologically identical to the original tumor in some regions, but with fewer adipose-like cells, while other areas presented an endocrine architecture with oligo-like or pleiomorphic cells, and rosette-like arrangements of tumoral cells were seen around the thin vessels, with features similar to cellular ependymoma. The cells in the liponeurocytoma areas expressed synaptophysin, chromogranin A, and epithelial membrane antigen. Glial fibrillary acidic protein was expressed in some dispersed tumoral cells, in lipidized tumoral cells, and in reactive astrocytes. Cytokeratin was focally expressed in the ependymal region of the recurrence. The immunophenotype of our case, with glial, ependymal, and neuronal or neuroendocrine markers, suggest a neurocytoma with lipomatous and ependymal differentiation. This tumor resembled those derived from circumventricular organs. Its localization in the area postrema region led us to hypothesize that it may be derived from this circumventricular organ.
authors.affiliation: Hôpital Neurologique, BP Lyon Montchat, , 69394, Lyon Cedex 03, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Jouvet
authors.forename: Arielle
authors.initials: A
authors.lastname: Lellouch-Tubiana
authors.forename: Nathalie
authors.initials: N
authors.lastname: Boddaert
authors.forename: Michel
authors.initials: M
authors.lastname: Zerah
authors.forename: Jacques
authors.initials: J
authors.lastname: Champier
authors.forename: Michelle
authors.initials: M
authors.lastname: Fèvre-Montange
mesh_terms: D002551:Cerebral Ventricle Neoplasms / Q000473:pathology*; D002675:Child, Preschool; D002864:Chromogranins / Q000378:metabolism; D004805:Ependyma / Q000378:metabolism / Q000473:pathology*; D005260:Female; D020546:Fourth Ventricle / Q000378:metabolism / Q000473:pathology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D019394:Ki-67 Antigen / Q000378:metabolism; D008067:Lipoma / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D018306:Neurocytoma / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D009418:S100 Proteins / Q000378:metabolism; D016708:Synaptophysin / Q000378:metabolism; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D002864:Chromogranins; D005904:Glial Fibrillary Acidic Protein; D019394:Ki-67 Antigen; D009418:S100 Proteins; D016708:Synaptophysin