title: Differentiation of classic medulloblastoma into metastatic large cell medulloblastoma with focal rhabdoid differentiation in the absence of posterior fossa recurrence.
abstract: A case of classic medulloblastoma that metastasized, despite the absence of local recurrence, to extraneural sites 7 years after treatment is reported. The metastases were, in contrast to the primary tumor, of large cell type and displayed abortive myogenic and, in one site, also rhabdoid differentiation. The primary tumor expressed microtubule-associated protein 1B and neuron-specific nuclear protein (NeuN), and was desmin negative. The metastases were also positive for microtubule-associated protein 1B and NeuN, although the expression of the latter marker was weak and/or focal in two of four metastases and absent in the rhabdoid metastasis. They were, in contrast with the primary tumor, all strongly positive for desmin. The hSNF5/INI1 was expressed in the nuclei of all cells of the primary tumor and the metastases, including the one with rhabdoid differentiation. Two metastases were studied by cytogenetics. The composite karyotype of a large cell metastasis was 45~46,XY,add(1)(p36.1),t(2;8)(p21;q24.1),add(3)(q25),t(9;15)(q22;q13),add(12)(p11.2), +1approximately2mar,inc[cp12]/46,XY[12], while the rhabdoid metastasis contained additional changes including monosomy 22. These findings indicate that some rhabdoid (atypical teratoid/rhabdoid) tumors of the cerebellum and medulloblastoma may be histogenetically related.
authors.affiliation: Department of Anatomic Pathology, Scott and White Memorial Hospital, Scott, Sherwood and Brindley Foundation, The Texas A&M University System Health Science Center College of Medicine, 2401 South 31st Street, Temple, TX 76508, USA. ldonner@swmail.sw.org
authors.forename: Ludvik R
authors.initials: LR
authors.lastname: Donner
mesh_terms: D002454:Cell Differentiation / Q000502:physiology*; D002648:Child; D002868:Chromosomal Proteins, Non-Histone; D002892:Chromosomes, Human, Pair 22; D020732:Cytogenetic Analysis / Q000379:methods; D004268:DNA-Binding Proteins / Q000378:metabolism; D003893:Desmin / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008527:Medulloblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission / Q000379:methods; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009362:Neoplasm Metastasis / Q000235:genetics / Q000473:pathology* / Q000648:ultrastructure; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D018335:Rhabdoid Tumor / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000556:secondary; D000071796:SMARCB1 Protein; D014157:Transcription Factors
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D003893:Desmin; D008869:Microtubule-Associated Proteins; D000071796:SMARCB1 Protein; C513266:SMARCB1 protein, human; D014157:Transcription Factors; C085284:microtubule-associated protein 1B; D010751:Phosphopyruvate Hydratase