By Adem Lewis / in /


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 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 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 and those are
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 different types now these make up about 85% of all them
foments so only a small fraction lymphomas are Hodgkin’s lymphoma and
we’ll talk about that specifically 80% of these non-hodgkins lymphoma are B
cells where only 20% are T cells now of those 40% I’m sorry of those eighty
percent forty percent are from are actually are from follicles and 40% are
diffuse or form the fuse we’ll talk about though so follicles that means
they actually look like the parts of lymph nodes which is good because that’s
a mature effect of the lympha of the of the lymph tissue whereas if it’s
diffused 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 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 going to 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 I 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 cleave it cleaved there 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 all right 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 look 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 and 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 and intermediate grade so this is low
grade intermediate grade and high grade and 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 diffuse with
diffuse proliferation of mature small lymphocytes that 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 could 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
going to 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 is 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
sious what is 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 but
just be aware that these typically have so 85% of them have this translocation
okay they’re usually larger and diffuse okay so there 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 will 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 a cure with occur with malt which is mucosa associated lymphoma
lymph tissue and it stays at the site of 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 going
to 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 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 going to 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 is 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 going
to stead of writing the five numbers I’m going to give you my gnomonic 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 t-cell leukemia that
one can also do 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 do 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 are 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 then 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
therefore seseri syndrome is also a t-cell lymphoma and it’s found
peripherally in the blood okay what’s the last S for here this is a small okay
so that’s unusual because it’s a high-grade usually 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 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 human herpes family so just be aware of that
okay so again small cell non cleave Burkitt’s lymphoma think of starry sky
think of the 814 translocation the seeming gene immunoglobulin is
associated with that and epstein-barr virus okay
the last one is immuno blastic lymphoma and these are can be T cells or B cells
typically they’ve got about a 50 percent cure rate 50% from an immunological
disorder of some sort 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


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