welcome to another MedCram lecture we're going to talk about lymphomas and
lymphoma is a pretty big topic so we sort of have to break it down but let's
talk about lymphomas in general there are two major types of lymphomas I want
to sort of break this down for you here there's Hodgkins and then non-hodgkins
lymphoma there's also another way of breaking it down and that's into the
different types of cells that are creating the lymphoma so what is a
lymphoma a lymphoma is simply a collection of
white blood cells for whatever reason either they're not dying and they're
collecting or there's something wrong with how the immune system is causing
them to replicate and they're replicating out of control so we can
divide it into the two types of lymphocytes and there are B lymphocytes
and there are T lymphocytes now the way that they can check this is by looking
at markers the thing to remember here and this is kind of like a primer here I
want to give you in terms of pathology the thing you have to look for are the
cd19 that's a marker for B cells where the T
cells as you may recall are simply cd4 or cd8 okay so look out for those
now there's also another type of lymphoma that you can also have almost
in a different category but we'll say it anyway and those are dendritic languor
and cells and those are the antigen presenting cells as you may recall and
as you may recall also they are s100 positive and those are little Berbick
granules that look like little tennis rackets in the cells so just be aware
that these markers there's s100 the cd4 cd8 and the cd19
so that's an important distinction there between b-cells and t-cells okay so
let's talk about specifically non-hodgkins lymphoma we're going to
talk about the different types now these make up about 85% of all them foeman's
so only a small fraction of lymphomas are Hodgkin's lymphoma and we'll talk
about that specifically 80% of these non-hodgkins lymphoma our b-cells
we're only 20% our t-cells now of those 40% I'm sorry of those eighty percent
forty percent are from follicles and 40% are diffuse or form diffuse we'll talk
about those so follicles that means they actually look like the parts of lymph
nodes which is good because that's a mature effect of the lymph of the of the
lymph tissue whereas if it's diffuse that's not good that means it's more
primitive and not as differentiated so that's that's not a good finding so
those are two different things there now and the 20% of the t-cells they are
always diffuse now why is that it's because B cells make up your lymph nodes
and T cells don't and where do you see follicles you'll see them only in the
lymph nodes so if you're gonna have a multiplication of B cells half the time
they look like they should as they do in lymph nodes and the other half
they're just diffuse now let's talk about what are the characteristics of a
lymphoma that make it good what I mean by good is less proliferative or bad
more proliferative so let's talk about less proliferative or more proliferative
so the things that you have to look at are whether or not they're cleaved so a
cleaved means that you've got a cell and they've got like a little thing in it
okay they're not smooth they've got a little cleavage cleaved
they're okay kind of where they get the term cleavage from but a little bit of a
cleave something is dividing it more proliferative would be non cleaved okay
what's the next characteristic alright what about small versus large so small
it's going to be less proliferative large is going to be more proliferative
if they look mature that means they looked more like the normal thing which
means they're not going to be as proliferative and if it's immature that
means it's going to be more proliferative it's another
characteristic we talked about this already follicles versus diffuse okay so
just looking at at the different types of lymphomas and these are important
because we'll actually describe some of these lymphomas with these words to see
if it's a small cleaved or a small non cleave they're mature with follicles all
of this boils down to is how aggressive is this lymphoma going to be and that's
important to know for prognosis okay so once again let's go back to our
non-hodgkins lymphoma and I want to divide them because there are different
grades okay there's a low grade an intermediate grade and a high grade so
let's let's look at that now and let's make up some divisions here so we've got
low grade an intermediate grade so this is low grade intermediate grade and high
grade now let's just go through some of these there's for low grade lymphomas
that you should know and we'll describe them okay the first one is a small
lymphocytic lymphoma and this type of lymphoma kind of looks like CLL
okay that's chronic lymphocytic leukemia it also kind of looks like Waldenstrom's
macroglobulinemia it can secrete IgM it's basically a b-cell with diffuse
proliferation of mature small lymphocytes now you probably have
figured that out that even though it's diffuse you've got mature small
lymphocytes which makes it a low-grade so we're going to be looking at things
here that are small that are cleaved typically but not always so small
lymphocytic lymphoma kind of looks like CLL again it's the thing that you're
gonna see is number one it's a b-cell it's diffuse which is kind of unusual
for a low-grade but there you have it and it's mature and they're small okay
so that's number one that's the first one that you should
know if you see a small lymphocytic lymphoma it's kind of almost like a
leukemia in that sense the next one that you should know is called mycosis
fungoides
this is a skin lymphoma and it's usually involving it's it's because of the
t-cells so mycosis fungoides is a low-grade lymphoma of the skin called
mycosis fungoides pretty straightforward the next one that you should know is
probably one that you should know because you see it on tests and this is
the follicular lymphoma x' follicular lymphoma x' okay why is this important
it's important because there's a certain translocation that occurs that causes
this what does a translocation it's when one gene comes off and slips on to
another gene in this case it's on different chromosomes so this is what we
call a 1418 translocation of the bcl-2 gene now why is that an important gene
because this is the gene that does something called a plateau --ss don't
say apoptosis it's a pitocin the PT is ptosis so a Patou --ss what does a
pitocin is when the cell dies this is the gene that causes the cell to die
which is good because cells are supposed to die if they don't die they accumulate
and if they accumulate you get a follicular lymphoma what happens is this
translocation causes this gene to malfunction which prevents the body from
getting rid of these cells that should no longer be there this can sometimes
actually progress to the next phase which is an intermediate grade so 85% of
them have this translocation okay they're usually larger and diffuse and
you also here's the other key that you see you can see larger and diffuse are
the ones that go over to the intermediate but how do these typically
look on their own typically these are small
and they're cleaved and you should already know that because small and
cleaved are typical features of a low-grade lymphoma so small cleave
follicular lymphoma think of the 14 18 translocation of the bcl-2 a potosi gene
okay that probably you'll see on tests the last one that you will see is these
something called an extra nodal lymphoma okay these extra nodal lymphomas
typically in here with occur with malt which is mucosa associated lymphoma
lymph tissue and it stays at the site at the origin and usually get these
low-grade with guess what small lymphocytes okay so these are the four
different types of low-grade lymphomas okay what about intermediate well gonna
give you a break here because there's only two that I want to talk about in
terms of intermediate one of them is a follicular large cell lymphoma and
typically that can occur from these smaller ones that actually turn out to
be larger from this 14 18 translocation so you can get an intermediate grade
follicular large cell lymphoma okay so you just see the large cells and the
other type here you can get is something called a diffuse lymphoma and here
you'll see b-cells and remember we said half the B cells can form diffuse or
half confirm follicles well these are gonna form diffuse no follicles or you
can get a t-cell mix them FOMA okay so those are the two that I think you ought
to know there's the follicular large cell lymphoma and then there's the
diffuse lymphoma so that you can get in general alright let's go to high-grade
these are the ones that we don't like to see typically we see blasts and they're
not cleaved and they're large and there's five of them and I'm just gonna
instead of writing the five numbers I'm going to give you my no modoch for
remembering and lassie l/a s-s-i just like the dog
Lassie okay what's the L stand for it stands for lymph oblast ik lymphoma so
what do you need to know about that this is the one that can go to leukemia okay
and it is T cell typically unfortunately it's accounts for 40% of childhood
lymphomas and it can go to the CNS and the skin that's where you see it so
lymphoblastic lymphoma can progress to leukemia T cell and 40 percent of
childhood lymphomas central nervous system and skin can go to mediastinal
lymph nodes and things of that nature okay that's lymphoblastic lymphoma a
stands for adult t-cell lymphoma or adult he cell leukemia that one can also
do it go to it there is a virus associated with this one called htlv-1
you should probably remember that it's very common it's actually it's more
common than not in Japan more common than outside of Japan and the Caribbean
and what did they see you see hypercalcemia in this one so
that's a finding so if they ever give you a patient on presentation with a
lymphoma it's aggressive the patient has high
calcium or they're Japanese or from the Caribbean I want you to think of adult
t-cell lymphoma they may ask you what's the virus associated with this it's not
HIV but it's htlv-1 all right that an S stands for Cezary syndrome s e-z ary s
syndrome I basically just want you to think of Cezary syndrome as a more
aggressive form of mycosis fungoides it's a malignant form instead of just
staying in the skin it spreads and remember that mycosis fungoides is a
t-cell lymphoma the for seseri syndrome is also a t-cell
lymphoma and it's found peripherally in the blood okay what's the last s4 here
this is a small okay so that's unusual because it's a high-grade usually see
large but here it's a small but it's non cleaved lymphoma and the name that you
might associate with this if you've seen it before is Burkitt's
also you may see this on a histological slide if you get a chance to look at
that as the one with the starry sky okay and it's also so soot associated with
the translocation it's associated with the 814 translocation and the gene is
the see Mick this is a tyrosine kinase gene that does intracellular signaling
and it's the signal to make immunoglobulins IG and so these things
just start making immunoglobulins they start dividing every single time they
want every single time the cell goes to make an immunoglobulin instead of making
an immunoglobulin it divides and you know these cells like to make
immunoglobulins so you can imagine how fast these cells are going to divide so
it could actually be leukemic and you can see GI tumors the famous picture is
an African with a very large jaw or very large neck mass and this is also
associated with EBV epstein-barr virus which is for human herpes family so just
be aware of that okay so again small self non cleave
Burkitt's lymphoma think of starry sky think of the 814 translocation the C
McGee n-- immunoglobulin is associated with that and epstein-barr virus okay
the last one is immuno blastic lymphoma and these can be T cells or B cells
typically they've got about a 50 percent cure rate 50 percent from it
immunological disorder of some so it could be could be from non-hodgkins
lymphoma as well but just remember that I is immuno
plastic so what are the hot points here that you should remember the hot points
here that you should remember about lymphomas is they're divided into three
sections you've got the low grade the
intermediate grade the high grade remember the things that make it low
grade and high grade so we're talking about whether or not it's cleaved or non
cleaved small or large mature or immature
follicles or diffuse I think the things that they would test you on here is
knowing these translocations because they are very key to test okay so
knowing which translocation goes which which type of lymphoma you should also
know about I think the adult he cell lymphoma that's a favorite one for test
questions I think memorizing what your high-grade lymphomas are would also be a
key point there as well I would also think that knowing that mycosis
fungoides is a t-cell lymphoma of the skin and that says urea syndrome is a
t-cell lymphoma that spreads from the skin I think that would also be a hot
point to know let's talk about Hodgkin's lymphoma in our in our next lecture but
thanks for joining us