Fuhrman et
al (1982) - Graded by most malignant feature even if only
focal
1 - Small, round uniform nuclei with
inconspicuous or absent nucleoli
2 -
Larger nuclei with irregular outline and small nucleoli present
3 -
Larger nuclei with irregular outline and prominent nucleoli
4 - Grade 3 features with bizarre, multinucleated cells, with or
without spindle cells
Skinner et
al (1971) - No evaluation of histologic pattern
I - Nuclei
indistinguishable from normal tubular cells
II - Nuclei only slightly larger
than normal tubular cells; nuclear outline slightly irregular
III - Nuclei moderately enlarged,
pleomorphic and with irregular outline
IV - Occasional common bizarre,
giant nuclei present
Arner er al
(1965)
I - Highly differentiated
tumors, sharply demarcated from surrounding tissue
IIA - Moderately differentiated tumors,
locally well circumscribed, but not necessarily
provided with
capsule
IIB - Moderately differentiated tumors poorly
circumscribed but not diffusely infiltrating
and / or
markedly polymorphous
III - Poorly differentiated, markedly polymorphous tumor,
which are diffusely infiltrating
tumors with
abundant growth in capillaries.
