All right, that's vein pathology.
In very short order, let's do lymphatic pathology.
This is going to be a little bit quicker,
so, pay attention.
Okay, so we have primary and secondary causes of
lymphatic vessel obstruction.
Primary causes are extremely uncommon,
but they're kind of interesting, so we'll
talk about them briefly in a minute.
The secondary causes are much more common
and that's because the lymphatics
are the track by which we sample
our various parts of our body,
looking for infection.
Well, those infections may not
just travel within the lymphatics,
they may actually affect the lymphatics,
you can have infections,
so inflammatory processes, infectious processes
Again, malignancy will travel
along lymphatics and lymph nodes.
So, lymphangitis is nothing more,
nothing more than acute inflammation
that's caused by bacterial seeding
of the lymphatic vessels.
They appear as red painful subcutaneous streaks,
you can actually see them,
you can see them originating from a wound
or some site of infection and you'll have
inflammation all the way along there,
should you choose to biopsy them.
It's often, not always,
but often associated with an
inflammation of the draining lymph nodes.
What's shown here in the green circle,
is a tender enlarged lymph node,
of a patient who had lymphangitis
and then had lymphadenitis.
So, infection inflammation
of the associated lymph node.
If the bacteria, are not
contained within the lymph node,
if we're not effectively
dealing with the infection,
they can pass into the venous circulation,
recall that, lymphatics eventually make
their way back up to the thoracic duct
and that eventually dumps
into the left subclavian vein,
so, if we don't clear, it at one of
these way stations then you can have,
bacteremia and sepsis.
Okay, so those are kind of the secondary ones,
and they're much more common.
Primary ones are kind of cool,
so we'll talk about them briefly.
So, you can have isolated congenital defects,
so, there are valves within the
lymphatics and if those valves don't work,
you can get a kind of a primary lymphedema.
There are familial syndromes
called “Milroy disease”
and there are others,
that lead to defective milking of the lymphatics,
it turns out that the lymphatics
have a nice little milking activity,
smooth muscle cells contracting
all along their length
and if that doesn't work appropriately,
if it's not organized in a
nice synchronized squeeze,
then you can get lymphedema.
Secondary lymphedema can occur with tumors,
obviously blocking flow,
it could be internal or external,
it can be surgical procedures
that sever lymphatic connections
and classically, when we have
a woman with breast cancer,
we will also take out these
the axillary lymph nodes,
associated with that breast and when we do that,
we sever the lymphatics and
then in the draining tissue,
the arm, that would normally
drain into those lymphatics,
there's no place to go.
Post radiation fibrosis, similarly,
will cause lack of flow through
the lymphatics in the lymph nodes.
And then filariasis, so a parasitic infection,
a certain worm, that has a peculiar
predilection for lymphatics,
and that will cause elephantiasis,
that's the disease that you should remember,
associated with filaria.
And then any inflammatory scarring,
anything that will
destroy, fibrose, compromise
the normal lymphatic flow,
will also give you secondary lymphedema.
So, what's happening here?
So, we have some sort of lymphatic injury,
there's increased hydrostatic pressure,
because we're not able to
drain fluid out of the tissue,
that's associated with that,
that gives rise to edema.
As we accumulate edema fluid in there,
there’s going to be various fibrogenic mediators,
that are going to lead to the
deposition of extracellular matrix
and we're going to get fibrosis.
Because of the edema,
limiting flow into the tissue that
will also compress venous structures,
that have low pressure,
and with the fibrosis,
we're going to end up with
inadequate tissue perfusion,
and that will manifest the skin ulceration.
As we get accumulating edema and poor perfusion,
we get what's called a brawny
induration of the overlying skin,
so, it becomes brown, and will
also become quite edematous,
and it can look like orange peel,
so again, trigger alert next
picture not really pleasant.
If the lymphatics dilate, they can rupture,
you can get an accumulation
outside of the lymphatics,
of lymph that would normally drain.
If it was in the tissues you get edema,
but in cavities we can get a chylous ascites,
a chylothorax and a chylopericardium,
so, this is just accumulation of lymph,
in various tissues or various spaces,
such as, the peritoneum, the thorax
or the pericardium.
This is the image that I warned you about.
So, this is a very classic orange peel appearance,
if you say it in French, it sounds
better it sounds “Peau d'orange”
which is, the orange peel.
And this is overlying a breast carcinoma,
where the breast cancer has
completely obstructed the lymphatics
and we have this, kind of edema and
involvement of the overlying skin.
This is a patient who had
complete right sided opacity,
shown here on chest x-ray,
that is a chylothorax.
This is due to a rupture of
a major lymphatic vessel,
within the thorax, probably caused by malignancy.
And with that we've covered, in
pretty quick order venus pathologies
and lymphatic pathologies
you've gotten some take-home messages to remember.