Our topic now brings us to paraneoplastic syndromes and
the different times in which you would expect to see
certain syndromes and the associated cancer. Our first
paraneoplastic syndrome will be acanthosis nigricans.
Acanthosis nigricans means thickening of the keratinocyte
giving it thus a dark colour. You might find this
underneath the armpit or maybe the back of the neck and you
should be thinking about maybe pancreatic or gastric adenocarcinoma.
A topic here, this patient "Hey Doc, wake up in the mornning
and I feel a little tired. Takes me a while to get going.
5, 6 o'clock in the evening I feel great. I wish my work
day actually started at 5pm." In this patient,
as the day wears on, he or she gets stronger. Not myasthenia
gravis, the opposite. This is Eaton-Lambert myasthenic syndrome.
Associations, small cell lung cancer. With small cell, we
will take a look at 3 different associations.
This is one of them. So what is Eaton-Lambert and what does
it do? If you remember correctly from your Immunology,
that you would have your immunoglobulin and autoantibodies.
That are then attacking instead of acetylcholine receptors,
they are attacking the calcium channels. Now I need you to
picture this. Picture neuromuscular junction. Are you picturing it?
Neuromuscular junction. Normally you would release what from the
pre-synaptic terminal. Acetylcholine. What does it then bind to
the post-synaptic terminal? Acetylcholine receptors. No problem
there. What caused the fusion of your vesicle to the membrane in
the pre-synaptic terminal. A trigger would be voltage gated calcium
channels. Voltage gated calcium channels. These are the channels
that are then being attacked by auto antibodies. So if the voltage
gated calcium channels are dead, the patient wakes up in the morning,
does'nt feel that great. Dr. Raj but how are your patient getting
better? How is your patient getting stronger? The body will find a way.
The body will find a way in which it releases acetylcholine from
the neuromuscular junction or from the pre-synaptic terminal.
You have any problem with your receptors in Eaton-Lambert? So
therefore your patient is then going to present with?
well you will have your end plate potential then have action
potential and then down it goes to the T-tubules,
skeletal muscles and contraction. Right. Small cell lung
cancer's paraneoplastic syndrome. Hypertrophic osteoarthropathy.
What does it look like? Take a look at the fingers here. Those
fingers are clubbed. It looks like it's clubbed. But this is
the bone underneath the nail that is undergoing hypertrophy. Your
differential, bronchogenic carcinoma. Hypertrophic osteoarthropathy.
Why? We don't know exactly. Then you have NBTE. Stands for
non bacterial thrombotic endocarditis. And for this
you should be thinking about mucous secreting cancers and these
include examples such as pancreatic and colorectal cancer.
Where are you by the way? Endocarditis. Most likely on the valves
of your heart. Non bacterial, sterile. Think about where you are
and know it's interesting associations. Seborrheic keratosis.
The picture here on the right that you are seing,
the first picture will be that of your Leser-Trelat sign. This
to you should also indicate adenocarcinoma, and usually
it will be the diffuse type in which the E-cadherin will be
negative. Another name for Leser-Trelet is called
seborrheic keratosis. And on your boards, do not confuse this
with, good, actinic keratosis. One has nothing to do with the other.
Here we have superficial migratory thrombophlebitis. This is
your pancreatic cancer. When we talk about GI and pancreatic
cancer, I will then talk to you about this and we will refer to
it as being as Trousseau Syndrome. Not Trousseau sign.
Trousseau sign, yes, you have learned correctly. That your,
let's say tapping of the facial nerve, Chovstek.
Or maybe carpopedal spasms with a brachial cuff. That's
Trousseau sign, hypocalcemia. Now the picture on the far right
is the darkening of the skin underneath the armpit that's
acanthosis nigra. Nigra means dark.