Pap stain: Medium power
Cluster of medulloblastoma cells with high N:C ratios, dense dark chromatin and scant cytoplasm
Pap stain: High power
Cluster of medulloblastoma cells. Compare size with lymphocytes and red blood cells in the background. Note the rosette formation in the group
Pap stain: High power
Cluster of medulloblastoma cells with high N:C ratios, dense dark chromatin and scant cytoplasm
Features
• Predominantly seen in children and young adults
• Small round blue cell tumor
• Small cohesive groups
• Small round blue cells
• Classic rosettes usually not seen in CSF
• Slightly larger than normal lymphocytes
• Scant cytoplasm
• High N:C ratios
• Hyperchromatic nuclei
• Nuclear molding may be seen
• Chromatin dense
• Nucleoli visible to prominent
• Watson CW et al. Acta Cytol. 1977 Jan-Feb;21(1):40-7.