title: Cellular schwannoma: a distinct pseudosarcomatous entity.
abstract: Eighteen cases of cellular schwannoma, a recently delineated benign entity, are described. These tumours present most often in middle-aged adults of either sex and show a predilection for the paravertebral region of the mediastinum and retroperitoneum. More than half the tumours macroscopically arose from a nerve but none was associated with von Recklinghausen's disease. The light microscopic features are remarkably consistent but are not immediately recognizable as neural in type. Means of distinction from a malignant nerve sheath tumour and from a variety of other soft tissue tumours are discussed. Immunohistochemical positivity for S-100 protein has been demonstrated in 17 of the 18 cases. Prolonged follow-up has revealed local recurrence in only one case; none has metastasized.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000032:analysis / Q000473:pathology*; D009418:S100 Proteins / Q000032:analysis; D012509:Sarcoma / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000032:analysis / Q000473:pathology*
chemical_list: D009418:S100 Proteins