title: Leukoencephalopathy around a tumor cyst following intracystic methotrexate injection.
abstract: A 4-year-old female with choroid plexus carcinoma developed progressive disturbance of consciousness 2 years after postoperative treatment with radiotherapy, chemotherapy, and focal methotrexate injection into a residual tumor cyst. Magnetic resonance imaging revealed white matter lesions localized around the expanding large cyst. A malignant recurrence of choroid plexus carcinoma with a propensity of cerebrospinal fluid overproduction was suspected. However, daily drainage of cerebrospinal fluid from the cyst and treatment with glycerol and dexamethasone achieved improvement. Diffuse hypoperfusion over the lesions on single-photon emission computed tomography denied the possibility of residual tumor aggravation and together with subsequent atrophic changes confirmed that the lesions reflect localized leukoencephalopathy, possibly associated with methotrexate forced into the parenchyma as a result of the expanding intracystic high pressure.
authors.affiliation: Department of Reproductive and Developmental Medicine, Division of Pediatrics, Akita University School of Medicine, Akita, Japan.
authors.forename: Tamami
authors.initials: T
authors.lastname: Yano
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sawaishi
authors.forename: Aya
authors.initials: A
authors.lastname: Hirayama
authors.forename: Iwao
authors.initials: I
authors.lastname: Takaku
authors.forename: Goro
authors.initials: G
authors.lastname: Takada
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage*; D016545:Choroid Plexus Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D003560:Cysts / Q000134:cerebrospinal fluid / Q000209:etiology* / Q000473:pathology*; D006801:Humans; D007223:Infant; D015552:Injections, Intralesional; D007427:Intracranial Pressure; D008279:Magnetic Resonance Imaging; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage*; D009186:Myelin Sheath / Q000473:pathology
chemical_list: D000964:Antimetabolites, Antineoplastic; D008727:Methotrexate