CSF/brain smear cytology - Rcpa.tv

Brain smears:Normal:Normal cerebral cortex:-abundant neurons that are uniformly distributed-oligodendroglial cells with small round nuclei-microglial cells with small elongated nuclei-fibrillary background, branching meshwork of thin-walled capillariesNormal deep cerebral grey matter:-larger neurons often prominent-calcospherites may be seen in older patientsNormal white matter:-background neuropil is typically coarser and more fibrillary than that of grey matterbecause of greater proportion of myelinated fibres-mixture of oligodendroglial, microglial and astrocytic nuclei-less vascular-normal glial cell nuclei are small with no perinuclear cytoplasmNormal cerebellar cortex:-the granular layer of the normal cerebellar cortex is one of the most cellular regionsof the CNS-smears show hypercellular zones in a fibrillary background-most numerous cells are granule cells: round nuclei with central chromatin aggregate(targetoid appearance). Size of the nucleus is about that of a normal lymphocyte.-Purkinje cells: very large cell with pyramidal or bulbous shape cell body, 1-2prominent nucleoli, abundant granular cytoplasm, thick dendritic processes extendingfrom the cell bodySmears from normal cerebellar cortex may mimic a small round celltumour, esp. medulloblastoma. Normal granule cells are smaller and they do notmould. Purkinje cells are intermixed with the granule cells.Normal pituitary gland:-tougher to smear-cytological heterogeneity with cells of different sizes and nuclear patternNon-neoplastic lesions:Reactive gliosis:-smears are cellular than normal-cells show even distribution with no nuclear crowding-astrocytes have long radiating processes and stellate cytoplasm (neoplastic astrocytesdo not have long processes)-beware: mitoses may be seen but morphologically normal and usually sparse-background neuropil tends to be more coarsely fibrillary than normal-characterised by evenly spaced astrocytes of uniform size with abundant eosinophiliccytoplasm and radiating long processes-if there are foamy macrophages or perivascular lymphocytes, a reactive processshould be first considered