Hello. Let’s take a look at
soft tissue pathology.
In soft tissue pathology, which technically
comes under connective tissue diseases.
What we will do is we’ll organize
our thoughts so that you know
that when a tumor arises from a
particular part of a soft tissue
that the nomenclature will tell you
what kind of signs and symptoms
you can expect in your patient.
Let’s say there’s a tumor arises in the
connective tissue but it’s a fat,
then the name will be lipo-,
and of course if it would
be a benign tumor,
you’d call it lipoma whereas if it was
liposarcoma, it would be obviously malignant.
Fibroblasts then you’re thinking fibro-.
If it’s from the muscle then you’d be using,
if it’s benign, then you’re
whereas if its rhabdomyo- then you’re
thinking skeletal muscle,
and leiomyo- would be of smooth muscle
type and the rhabdo- would be
of the skeletal muscle origin.
Nerves, obviously here
you’d call it neuro-,
and in the bones—the discussion that
we’ve had in orthopedics,
well then obviously you’re using the name
osteo- for bone, chondro- for cartilage.
There’s a table here to quickly demarcate the
differences between benign and malignant.
Histologically, in the description
that you want to keep in mind as
you describe the particular
tumor that you’re looking for
well if it’s benign then most likely small—
now you know these are just general rules
but doesn’t always have to
be exactly like this.
Malignant would be larger, in other words,
highly proliferating, and the more
malignant and more proliferative
a malignant tumor then becomes,
then you’re increased risk of course
of then invasive.
Benign tends to be superficial,
Benign tends to be slow growing
because of decreased mitotic rate.
Malignant would be fast growing so
obviously much more proliferative.
If it’s benign, then you’re
thinking about the cytoplasm
being much more than the nucleus
because the mitotic rate and the
proliferation rate is much lower,
whereas if it is malignant, then you
can expect a lot of nucleic activity
so therefore you can expect; therefore,
to see quite a bit of well,
nuclear activity, so therefore,
Your nuclear-cytoplasmic ratio
will have increased when you’re describing
tumors that are of malignant
nature in general. Correct?
A benign nuclei—well that would
mean that the contours
of the chromatin are smooth
and inconspicuous nuclei
whereas if its malignant, as you can
expect, there’s increased proliferation
and that increased nuclear activity
which is quite prominent,
is often times referred to as being “ugly.”
If it’s benign, then the tumor
tends to be well-circumscribed,
or are exceptions of course.
Malignant tends to be infiltrative—you’re
worried about compromise
of that membrane and invasion taking place.
In malignancy, expect there to be
increase, frequent mitoses.
Metaphase is something that you’d
be looking for in the nuclei
and then necrosis is something that also
takes place because of increased
destruction of the cells.
soft tissue issue that we’ll take a look
at that’s benign is called lipoma.
Of course, lipoma referring to lipid,
more common soft tissue
tumor of adulthood.
Well-circumscribed as you can expect
because we know that it’s benign,
most often subcutis of the
proximal extremities or the trunk.
If we take a look at the histologic
picture to the right,
you’ll notice these clear
vacuoles that are appearing
and these clear vacuoles represent
the fact that they are filled with lipid,
. Soft, mobile and painless are
descriptions that you’re
looking for in terms
of signs and symptoms from your patient
or from you observing.
If the lipoma
is no longer benign,
but with that said, I can’t say
that the liposarcoma,
which is the topic here, comes from
lipoma. So be careful.
So the most common sarcoma
of adults arguably
Almost never seen in children.
Age is middle age and above.
Arise in the deep tissue whereas lipoma
was superficial with subcutis
of the proximal extremity.
Liposarcoma will be deep, in other words,
there’s possibility of increased infiltration
and worry about invasion,
and if there’s invasion,
sarcomas of course tend to then
spread via ________ route.
They do have the characteristic lipoblasts,
which I’ll show you in a second,
and so therefore, what I mean by this is
the well-circumscribed type
that I showed you earlier for lipoma,
in which yes, you find your
vacuoles that are clear,
but you’ll compare that to what I’m
going to show you next,
which is lipid vacuoles indented
with the central nucleus
because of these cells that
are filled with lipid.
Liposarcoma. As I said, be careful.
Lipoma will be the benign, liposarcoma
would be the malignant.
It doesn’t mean that the liposarcoma arose
from the lipoma. Be careful.
Most of the time they do not.
There is 1 major exception I’ll tell you
now, and that’s your chondrosarcoma.
The chondrosarcoma may
arise from enchondroma
that would be 1 big exception in which,
at times, you have a malignant tumor
there—a bone tumor,
a cartilage bone tumor that is arising from
your benign cartilage tumor.
Here are the lipoblasts that I promised
that I would show you.
If you take a look in the middle here,
we have these big, plump, fat cells
and then in the periphery are the nuclei.
Rather characteristic of liposarcoma
whereas earlier when I showed you a picture
of lipoma, it definitely did not look
as dangerous, as congested as which.
On the same token, I want you to
keep in mind a differential
of liposarcoma known as nodular fasciitis.
So nodular fasciitis is a
It has nothing to do with malignancy.
Now you would have these plump fibroblasts
kind of like the picture
that I showed you earlier,
but that would basically be the
only, only similarity.
The history would be completely different
from that of liposarcoma.
A nodular fasciitis patient often times
give you a history of trauma,
and wherever that trauma might have
taken place, you have rapid growing
a mass on the forearm, for example
well, like a sarcoma, you would expect
there to be increase in proliferation,
you would see increased mitoses,
and you’d find a myxoid background.
Here’s a picture of nodular fasciitis
fasciitis in which these may then appear
as being lipoblasts, but they’re not.
And what you’re focusing upon
are these green arrows,
and those green arrows are then
pointing to the areas of mitoses
that are increased, and
in which the chromosomes are lined up
right smack dab in the middle
about to divide.
History of trauma is what you’re looking
for most likely in nodular fasciitis.