Table 3

The key distinguishing features of serrated adenocarcinomas23

SubtypeDetailed appearances
SerratedWell-moderately differentiated glands in which the epithelium has a serrated appearance
Eosinophilic cytoplasm—may be intense*
Vesicular (open chromatin) nuclei with basal location*
Dirty necrosis focal or absent
May possess small areas of mucinous differentiation
MucinousThe neoplastic cells are present usually as (poorly differentiated) cords of cells floating within the mucus pools
‘Serrated cytology’ retained
Areas with a ‘serrated morphology’ can form up to 50% of the tumour
TrabecularPoorly differentiated clusters and cords of neoplastic epithelial cells
‘Serrated cytology’ maintained
Lymphatic invasion common
This pattern may be seen at the advancing edge of serrated adenocarcinomas that are otherwise one of the other two subtypes
  • *‘Serrated cytology’ refers to the combination of these nuclear and cytoplasmic features.