title: Malignant primitive neuroepithelial tumour of soft tissues mimicking a cellular ependymoma.
abstract: A malignant small blue-cell soft tissue tumour in a 13 year-old girl is reported. By light microscopy the tumour showed prominent pseudo-rosettes suggesting peripheral neuroepithelial tumour (PNET) with ependymal differentiation or extraspinal cellular ependymoma. Ultrastructural and immunocytochemical findings helped in excluding an ependymal neoplasm (low-grade malignancy) and supported the diagnosis of malignant primitive PNET mimicking a cellular ependymoma (high-grade malignancy).
authors.affiliation: Department of Pathology, Porto Medical School, Hospital de S. João, Portugal.
authors.forename: J M
authors.initials: JM
authors.lastname: Lopes
authors.forename: M E
authors.initials: ME
authors.lastname: Paiva
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000032:analysis; D003937:Diagnosis, Differential; D004806:Ependymoma / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008940:Mitotic Index; D009363:Neoplasm Proteins / Q000032:analysis; D009447:Neuroblastoma / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D013848:Thigh
chemical_list: D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins