Separation of Benign vs Malignant Adrenal Cortical Tumors Based on the Criteria of Weiss

Criterion

Definition

Points

nuclear grade

Fuhrman grade I or II

0

Fuhrman grade III or IV (see table below)

1

mitotic rate

<= 5 in 50 high powered fields

0

> 5 in 50 high powered fields

1

atypical mitoses

absent

0

abnormal distribution of chromosomes or excessive number of mitotic spindles

1

cytoplasm

clear cells > 25% of tumor

0

clear cells comprise <= 25% of tumor

1

architecture of tumor

not diffuse

0

diffuse if more than one third of tumor composed of patternless sheets of cells

1

necrosis

absent

0

present if occurs in at least confluent nests of cells

1

invasion of venous structures

absent

0

unequivocal invasion of endothelial-lined vessel with smooth muscle as component of the wall

1

invasion of sinusoidal structures

absent

0

unequivocal invasion of endothelial-lined vessel without supporting tissue

1

invasion of capsule of tumor

absent

0

present if nests or cords of tumor extended into or through capsule with corresponding stromal reaction

1

Nuclear Characteristics of Fuhrman et al, based on most malignant area (even if focal)

Grade

• round, uniform nuclei without irregularities in outline

• nuclei approximately 10 µ in diameter

• inconspicuous or absent nucleoli under high power (400x)

I

• nuclei show irregularities in outline

• nuclei approximately 15 µ in diameter

• nucleoli apparent under high power (400x)

II

• nuclei show irregularities in outline

• nuclei approximately 20 µ in diameter

• prominent, large nucleoli apparent at low power (100x)

III

• nuclei show irregularities in outline

• nuclei approximately 20 µ in diameter or more

• prominent, large nucleoli apparent at low power (100x)

• present of bizarre nuclei, multilobed nuclei, heavy chromatin clumps

• presence of spindle-shaped cells resembling sarcomas

IV