Spinal cord lesions--pathologist point of view.

Spinal cord, a delicate organ can be effected by a variety of lesions. Subtle clinical features may be hathinger of a massive inflammatoRy orneoplastic process. Recent advances in radio imaging such as computerized tomography, magnetic resonance imaging and bone scintigraphy have broadened our horizons. Through these techniques one cannot only localize the lesion but under guidance obtain tissue for the diagnosis. Most of this is in the form of cytologic smear preparation. However, this is usually adequate for a person familiar with cytologic appearances of various lesions to reach a diagnosis. A part of this tissue can be used to form a cell block which can be used for special stains and immunocytochemistry. Key features of lesions are: Whorls and psamomma bodies of meningioma. Cells on immunohistochemistry are positive for vimentin and epithelial membrane antigen (EMA). Long club shaped nuclei of Antoni A component of a schwannoma 1. Cells are positive for S-l00 protin, Leu 7 and vimentin. Papillary structures formed by ependymoma. Cells are positive for Glial Fibrillary Acidic Protein (GFAP), EMA and cytokeratin. Hairlike processes of pilocytic astrocytoma. Pluinps eosinophilic cells, stained for GFAP in gemistocytic astrocytoma. Anaplastic cells with highN:C ratio in glioblastoma. Uniform cells arranged in Zeilballen in a paraganglioma. These are surrounded by S-l00 positive sustentacular cells. Atypical lymphoid cells with coarse chromatin and prominent nucleoli of a lymphoma. These may be primary or first manifestation of a systemic disease 2. Cells are positive for leukocyte common antigen (LCA) and Pan B or Pan T markers. Metastasis, epidural or intramedullary may show squamoid glandular or sarcornatous features 3. Osteoclast giant cells should suggest a bony lesion of vertebra especially osteoclastoma. Presence of granulomas would narrow the differential diagnosis. Of course tuberculosis will be on the top of list in this country. Viruses may be diagnosed by virtue of their inclusion bodies such as herpes simplex and cytomegalovims. There are several inflammatoiy and reactive processes, which may simulate neoplasm. Notable amongst these are demeylinating diseases, histiocytosis and xanthomatosis 4 , plasma cell granuloma 5 , Rosai-Dorfman disease 6 , Castlernan disease 7 and amyloidoma 8. All these can only be diagnosed if tissue is made available. These are rare lesions but do matterto individual patients. In this issue there is anarticle 9 analyzing lesions causing cord compression. This may not be entirely representative, e.g., in oncology service metastasis will be the conunonest cause similarly data Trom …