CSF/brain smear cytology - Rcpa.tv

Normal megakaryocytes:-single; never form cohesive groups-multinucleation: bag of eccentric nuclei-may have very bizarre irregular hyperchromatic nuclei-low N/C ratio with abundant cytoplasm-look for other cell types: myelocytes, normoblasts, etcVentricular fluid from shunt or reservoir:-frequently contain ependymal / choroidal cells in large numbers-fragments of normal grey and white matter containing neurons, astrocytes,oligodendrocytes, corpora amylacea and capillaries-more neutrophils and eosinophils, in response to ventricular wall irritationNormal neurons:-usually have prominent nucleoli-low N/C ratio-smooth nuclear membrane-cytoplasm may have Nissl substance-cytoplasmic processesBloody background:-usually implies traumatic tap (peripheral blood contamination)-may also be secondary to subarachnoid haemorrhage-problems:-entrapped inflammatory cells: does not mean meningitis-entrapped malignant (e.g. leukaemic) cells: does not necessarily mean meningealtumour involvement-not suitable for cell count-may take days to weeks for changes to resolve post traumatic tap-criteria for bloody background:-grossly bloody fluid in specimen tube-macroscopically bloody cytospin->90% of the cytospin covered by overlapping red blood cellsIncrease in neutrophil count:-bacterial meningitis-early stage of viral, TB or fungal meningitis-ischaemia-recent surgery-neoplasiaIncrease in lymphocyte count:-nonbacterial infections-multiple sclerosis-Guillain-Barré-syringomyelia-AIDSIncrease in eosinophil count:-drug reaction