Table 1 Histological features according to Edmondson and Steiner (ES) and WHO classification
Classification | Grades | Architecture | Cytology | Other features |
|---|---|---|---|---|
Edmondson and Steiner | I | – | – | Areas of carcinoma where distinction from hyperplastic liver is difficult |
II | Trabecular, frequent acini (lumen varying from tiny canaliculi to large thyroid-like spaces) | Resemblance to normal hepatic cells; larger nuclei; abundant acidophilic cytoplasm | Cell borders sharp and clear cut; acini containing bile or protein precipitate | |
III | Distortion of trabecular structure, acini less frequent than grade II | Larger, more hyperchromatic nuclei, granular but less acidophilic cytoplasm | Acini are less frequent; tumor giant cells may be numerous | |
IV | Medullary, less trabeculae, rare acini | Highly hyperchromatic nuclei, scanty cytoplasm, with fewer granules | Loss of cell cohesiveness; giant, spindle or short-plump cells can be found | |
World Health Organization | Well differentiated | Thin trabecular, frequent acinar structures | Minimal atypia | Fatty change is frequent |
Moderately differentiated | Trabecular (3 or more cells in thickness) and acinar | Abundant eosinophilic cytoplasm, round nuclei with distinct nucleoli | Bile or proteinaceous fluid within acini | |
Poorly differentiated | Solid | Moderate to marked pleomorphism | Absence of sinusoid-like blood spaces | |
Undifferentiated | Solid | Little cytoplasm, spindle, or round-shaped cells | – |