Practice English Speaking&Listening with: Extrapulmonary TB (part 1) | Infectious diseases | NCLEX-RN | Khan Academy

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Voiceover: This is Charles Prober.

Voiceover: And I'm Morgan Theis and today we're going to talk

about the extrapulmonary disease associated with tuberculosis,

which I find kind of interesting,

because I always think of tuberculosis as a lung disease.

Voiceover: In fact, you're correct, Morgan

that the most prominent infection associated with tuberculosis

is pulmonary disease, is lung disease,

but extrapulmonary disease is also very important.

In fact, it's so important that we're going to make two videos

about extrapulmonary disease.

The first one we're going to focus on disease involving the lymph nodes

and the genitourinary tract and then the second one,

we're going to talk about involvement of the bones,

the central nervous system, the gastrointestinal tract, and the heart.

The reason that it's so important to give this much time

to extrapulmonary disease is that we call tuberculosis,

the bug infects one-third of the world's population.

After that initial infection, some go on and immediately develop disease

and others, as we talked about before, develop secondary disease

and it comes out later and the infection may present

in a myriad number of ways.

In fact, that's one of the reasons that tuberculosis is referred to

as one of the great imitators.

It can imitate so many other kinds of disease.

Two videos.

Voiceover: Okay, so TB, the great imitator.

Voiceover: Exactly and some of the other great imitators

people talk about these days are lupus, which is, of course,

not an infectious disease, HIV infection,

which is an infectious disease, Epstein-Barr virus infection,

which is a viral infection.

Those are other great imitators, but today we're talking about tuberculosis.

Voiceover: Okay and these are good things to remember

because since they can present in so many ways,

we always have to have them on our differential diagnosis,

so we don't forget about them.

Voiceover: Exactly.

The first site that I'm going to talk about, Morgan,

is the lymph nodes and I'm talking about that first

because it actually is the most common place that TB goes, after the lungs.

Voiceover: Okay and which lymph nodes are we talking about?

Because they're everywhere in the body, right?

Voiceover: That is true, they're everywhere in the body

and the infection of the lymph nodes can occur

anywhere in the body, but the most common sites

are posterior cervical, so the lymph nodes at the back of the neck,

and then another common site is the supra clavicular area,

so that space above the clavicle.

Oftentimes, when you feel a lymph node above the clavicle,

you appropriately think of some sort of malignancy in the abdominal area,

because that's a sentinel node, the supra clavicular lymph node,

but something to remember that can also cause that is tuberculosis.

One of the features of a lymph node infection with tuberculosis

is that the lymph nodes tend to be painless,

so they don't hurt the person, and also they tend

to be not particular tender, so when you push on them,

they also don't hurt the person.

They often have a lack of overlying redness or heat,

because there really isn't much of an acute inflammatory response,

it's more of a chronic, slow process,

so these lymph nodes tend to sneak up on you, gradually enlarging.

As they gradually enlarge, some of them, however, can,

because it's a long-term process, can actually cause fistulas tracks,

that is a connection that goes from the lymph node

all the way up to the skin with drainage.

Voiceover: Oh gosh.

Voiceover: So if you see a fistulas track associated

with an enlarged lymph node, tuberculosis should be on your list.

The way these are diagnosed is that a sample of the lymph node

may be obtained and when looked at under the microscope,

you may actually see the tuberculous bacilli,

those little red snappers, as they're sometimes called,

or you may culture them if you don't actually see them.

Taking a chest x-ray of patients with suspected TB

in the lymph nodes is a good idea.

Voiceover: Right.

Voiceover: However, half the time or more than half the time,

the chest x-ray is negative, so don't be discouraged

from the diagnosis if the chest x-ray is negative,

because it oftentimes is negative.

Voiceover: Got it.

Voiceover: The next site that I'd like to talk about

is the genitourinary site and I'm talking about this site next

because after lymph node involvement comes the so-called GU,

or genitourinary involvement.

Thought to represent maybe 10 or 15% of cases

of extrapulmonary TB, as opposed to lymph nodes, that's more like 35%.

This is about half as common.

As is true of any infection that can involve the genitourinary site,

the kidneys and the genital area, the patients may have

very nonspecific complaints, such as blood in their urine

or pain when they urinate or needing to get up at night to urinate.

If you examine their urine under the microscope,

you may actually see white blood cells, so pyuria,

but you don't see any bacteria, typically, so that can be a finding.

Voiceover: I'm confused about that,

because why wouldn't the bacteria actually be in the urine?

Voiceover: The main reason is that the amount of tuberculous bacilli

that are often present at one of these extrapulmonary sites

is quite small and unless you either centrifuge the urine

or otherwise concentrate it and stain it with tuberculous specific stains,

you will not see bacteria.

That's in contrast to regular bacterial infections of the urinary tract,

where there is typically hundreds of thousands

to even millions of bacteria that show up in the typical stains that are used.

The term that's used here is when you see the white cells in urine

and you don't see any bacteria, and then you culture them

for regular bacteria, and they don't show up,

because TB doesn't show up on regular cultures,

it's culture negative pyuria.

Culture negative pyuria should make you think of tuberculosis.

Now, if you actually send those urine samples to the lab

and say, "I'm looking for tuberculosis," and they're set up

on tuberculosis specific media, then you often will grow the TB,

but if you don't think about it, you won't do the test,

and if you don't do the test, you won't make the diagnosis.

Voiceover: So you're asking for a TB culture?

Voiceover: Exactly.

I mentioned the chest x-ray in the context of lymph node involvement

and it's often negative.

With genitourinary involvement, the chest x-ray is often positive.

If you see culture negative pyuria and you're thinking of tuberculosis,

the chest x-ray may have value.

The other part of the genitourinary infection that I'll mention here

is specific to women and it's that tuberculosis may actually involve

the internal genitalia of women, that is the fallopian tubes

and the endometrium and the importance of recognizing that

is that this is one of the causes of infertility,

especially in the developing world, where tuberculosis is more common.

Men can also get infection of their internal genital organs,

including epididymis and the testicles.

They can also have prostate involvement.

Again, tuberculosis can cause an -itis, an inflammation in multiple organs.

In this case, in the genitourinary area.

Voiceover: And you say endometritis is one of them, as well?

Voiceover: Endometritis in women can occur

and I mentioned the fallopian tubes and when you have inflammation

in those areas, that can result in infertility.

The Description of Extrapulmonary TB (part 1) | Infectious diseases | NCLEX-RN | Khan Academy