Gradering esthesioneuroblastoom

Esthesioneuroblastoma grading (based on Hyams’ grading system)

Microscopic features	Grade I	Grade II	Grade III	Grade IV
Architecture	Lobular	Lobular	±Lobular	±Lobular
Pleomorphism	Absent to slight	Present	Prominent	Marked
NF matrix	Prominent	Present	May be present	Present
Rosettes	HR	HR	FW	FW
Mitoses	Absent	Present	Prominent	Marked
Necrosis	Absent	Absent	Present	Prominent
Glands	May be present	May be present	May be present	May be present
Calcification	Variable	Variable	Absent	Absent

NF neurofibrillary, HR Homer Wright pseudorosettes, FW Flexner-Wintersteiner rosettes