Approximately
10%
of
pheochromocytomas
and
35%
of
____________________
-
____________________
pheochromocytomas
are
malignant
.
Only
the
presence
of
metastases
____________________
malignancy
.
However
,
specific
histologic
features
help
to
differentiate
____________________
pheochromocytomas
with
a
potential
for
biologically
aggressive
____________________
from
those
that
behave
in
a
benign
fashion
.
Among
the
____________________
that
suggest
a
malignant
course
are
large
tumor
____________________
and
an
abnormal
DNA
ploidy
pattern
(
aneuploidy
,
tetraploidy
)
.
Common
metastatic
sites
include
bone
,
liver
,
and
lymph
nodes
.