title: Ependymoma with diffuse signet-ring features: report of a case and review of the literature.
abstract: Signet-ring cell ependymoma is a rare variant of ependymoma with only seven cases described in literature. Biological behavior and prognosis of this entity are not well-known until now. We present a case of a 49-year-old female with a history of headache and gait instability. Magnetic resonance imaging showed an upper cervical tumor with cystic component and mural nodule. The patient underwent surgery. Microscopically some cells displayed an eccentric nucleus compressed to the periphery by vacuolated cytoplasm. Perivascular pseudorosettes and ependymal rosettes were seen only focally. The cells were positive for glial fibrillary acidic protein and epithelial membrane antigen. The diagnosis was ependymoma with diffuse signet-ring features, grade II according to the World Health Organization. It may be difficult to diagnose this unusual variant of ependymoma especially on small biopsies or frozen sections. A complete examination of the specimen is recommended with immunohistochemical confirmation to rule out potential morphologic mimics, such as metastatic adenocarcinomas and gliomas in the differential diagnosis.
authors.affiliation: University and Hospital Trust, Anatomic Pathology, Department of Diagnostics and Pathology, Verona, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Cima
authors.affiliation: University and Hospital Trust, Anatomic Pathology, Department of Diagnostics and Pathology, Verona, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Beccari
authors.affiliation: University and Hospital Trust, Anatomic Pathology, Department of Diagnostics and Pathology, Verona, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Ghimenton
authors.affiliation: University and Hospital Trust, Neurosurgery, Department of Surgical Sciences, Verona, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Pinna
authors.affiliation: University and Hospital Trust, Neuroradiology, Department of Diagnostics and Pathology, Verona, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Beltramello
authors.affiliation: University and Hospital Trust, Anatomic Pathology, Department of Diagnostics and Pathology, Verona, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Chilosi
authors.affiliation: University and Hospital Trust, Anatomic Pathology, Department of Diagnostics and Pathology, Verona, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Brunelli
authors.affiliation: University and Hospital Trust, Anatomic Pathology, Department of Diagnostics and Pathology, Verona, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Eccher
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D001932:Brain Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D018279:Carcinoma, Signet Ring Cell / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D004806:Ependymoma / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D011237:Predictive Value of Tests
chemical_list: D014408:Biomarkers, Tumor
keywords: Ependymoma; Frozen sections; Metastatic adenocarcinoma; Signet-ring cell; Small biopsies