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