title: Cellular schwannoma. A clinicopathologic study of 29 cases.
abstract: A series of 29 cellular schwannomas is described in terms of their clinical presentation and course, light and electron-microscopic appearance, immunohistochemical properties and cytogenetics. The study indicates that cellular schwannoma can be defined as a subtype of classical schwannoma, characterized by spindle cells forming a compact fascicular, sometimes fibrosarcoma-like growth pattern, a low mitotic activity, a generally moderate nuclear and cellular polymorphism and a high degree of Schwann cell differentiation as seen by electron microscopy and immunohistochemistry. The tumour is characteristically located close to the vertebral column, in the mediastinum or retroperitoneum and has a benign course. Occasionally bone destruction and neurological symptoms develop. The clinical appearance together with the high cellularity, fascicular pattern and mitotic activity had led to the erroneous diagnosis of a soft tissue sarcoma in a few cases, and cellular schwannoma may thus be considered to be a pseudosarcoma. Immunohistochemically, cellular schwannomas appear to deviate from classical schwannomas and malignant peripheral nerve sheath tumours by their expression of glial fibrillary acidic protein. The chromosome analysis revealed a normal diploid stemline karyotype, with a variety of abnormal clones, including one with monosomy 22.
authors.affiliation: Department of Pathology II, Sahlgren Hospital, Gothenburg University, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Lodding
authors.forename: L G
authors.initials: LG
authors.lastname: Kindblom
authors.forename: L
authors.initials: L
authors.lastname: Angervall
authors.forename: G
authors.initials: G
authors.lastname: Stenman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D007621:Karyotyping; D008297:Male; D008479:Mediastinal Neoplasms / Q000032:analysis / Q000473:pathology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D009442:Neurilemmoma / Q000032:analysis / Q000473:pathology* / Q000648:ultrastructure; D009418:S100 Proteins / Q000032:analysis; D014407:Tumor Cells, Cultured / Q000473:pathology
chemical_list: D005904:Glial Fibrillary Acidic Protein; D009418:S100 Proteins