Chapter 24: Male Genital Pathology

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Welcome back to the Deep Dive.

I'm your host and today we are doing something a little different.

We're more focused.

Exactly.

Usually we take a wide array of articles and sort of throw them into the blender.

But today we are going strictly by the book.

We are taking a surgical laser focused look at Chapter 24 from the 2017 USMLE Step One Lecture Notes.

The topic is male pathology.

It is.

And joining me to help translate these, I mean let's be honest, these dense medical texts into something we can actually visualize and understand is our resident expert.

Welcome back.

It is wonderful to be here.

And you're right, this is a bit of a departure for us, but in a good way, I think.

I think so too.

We're doing a really rigorous walkthrough of the male reproductive system.

We're going to cover the penis, the testes and the prostate, essentially dissecting the text line by line to pull out those high yield concepts.

And for everyone listening, here is the mission statement for this Deep Dive.

We're translating this specific chapter.

We aren't diagnosing you.

We aren't giving medical advice and we are definitely not pulling in random Wikipedia facts.

No, absolutely not.

We're sticking strictly to the text provided.

We want to see exactly what a medical student needs to know about the mechanisms of disease right from the source.

Precisely.

This is about understanding the why and the how.

We want to look at the morphological changes, I mean what these diseases actually look like under a microscope, and the clinical connections that the text itself emphasizes.

It's foundational.

It is.

It's a foundational look at male health pathology and frankly,

some of it is pretty fascinating stuff.

So let's map this out for you, the listener.

We're going to follow the anatomical road.

We'll start with the penis covering malformations, inflammations, tumors.

Then we're going to move upstream to the testes, which is a massive section covering everything from like twisted cords to the very complex world of testicular cancer.

A very big section.

And finally, we end with the prostate tackling the big two conditions that really dominate that organ.

It's a very logical flow.

And I want to suggest a theme for today's dive if you're listening.

It's anatomy is destiny.

Anatomy is destiny.

I like that.

Because where things are located, I mean, it completely determines how the disease presents itself.

We're going to see that over and over and over again today.

Okay, let's do it.

Let's unpack this.

Part one, pathology of the penis.

The text jumps right in with congenital malformations.

Right at the start.

Specifically, problems with the urethral opening.

We have two terms here that look almost identical on the page.

Epospadias and hypospadias.

Help us distinguish these because I guarantee I'm going to mix them up.

And you wouldn't be the first.

I mean, it's a classic point of confusion.

But the text gives us a very clear geographical distinction.

It's all about where the plumbing exits relative to the shaft.

Okay.

Let's start with hypospadias.

Hypospadias.

All right.

This is defined as the urethral opening being on the ventral surface of the penis.

Okay, pause.

Ventral is one of those anatomical terms that can get a little twisty.

If we are talking about the penis, which side is ventral?

That's a great question.

You have to think of the penis in its anatomical position, which is effectively erect or lifting up.

The ventral side is the underside.

It's the side facing the scrotum.

Got it.

So hypospadias is a hole on the bottom.

Correct.

It's a developmental issue.

It's a failure of the urethral folds to close completely.

Now you compare that to hypospadias, the text defines this as an opening on the dorsal surface.

Which would be at the top side.

Exactly.

And there's a little mnemonic students often use.

It's not in the text, but it really helps lock in the definition provided.

Okay, let's hear it.

If you have hypospadias, the opening is on top.

So when you urinate, the stream goes up and hits you in the eye.

E for eye.

E for hypospadias.

That is vivid.

I will not forget that.

It sticks, doesn't it?

But you know, beyond just the location of the exit, the text wants us to understand the associations.

These aren't usually isolated incidents.

Right.

The notes mentioned that both of these conditions can be linked to other malformations.

Specifically, undescended testes.

Which creates a compounding problem, really.

And the text highlights two major clinical risks here.

One is recurrent urinary tract infections.

Which, you know, that makes sense.

The plumbing isn't flushing correctly.

But the second one is a heavy hitter.

Infertility.

Is the infertility just because the sperm isn't exiting at the right spot?

Is it purely mechanical?

Well, part of it is mechanical delivery, yes.

I mean, if the exit point is at the base of the shaft or halfway down,

natural insemination becomes mechanically very difficult.

Right.

But also, if it's linked to undescended testes, which we'll get to later,

you have issues with sperm production itself.

The factory isn't working right.

So it's a structural failure with some pretty serious functional consequences.

Absolutely.

Okay, moving on from birth defects.

Let's talk about inflammation.

The text throws two more tongue twisters at us.

Balanitis and balanopasthitis.

It really does sound like a spelling bee, doesn't it?

It really does.

So what is the distinction here?

It's purely a matter of anacomical extent.

It's just about how much is inflamed.

Balanitis is inflammation specifically of the gland's penis.

So the head of the organ.

Okay, just the glands.

Just the glands.

Balanopasthitis is inflammation of the glands and the foreskin, which is also called the prepuce.

So balanopasthitis is just more of it.

Exactly.

It's a more extensive version of the same underlying process.

And what is that process?

I mean, what's causing it?

The text is quite direct here.

The etiology is linked to poor hygiene, particularly in uncircumcised males.

So it's essentially a cleanliness issue.

In many cases, yes.

It's the accumulation of smegma or bacteria or other irritants that get trapped under the foreskin.

That creates a local inflammatory response.

It's a good reminder that, you know, basic hygiene is actually a preventative medical intervention.

It really is.

Okay.

Now here is a condition that I feel like has become part of pop culture because of all the late night TV commercials, but the actual pathology is really interesting.

Peyronie disease.

Ah, yes.

Peyronie disease.

The text has a very specific definition for this.

It calls it penile fibromatosis.

Fibromatosis.

That sounds like scar tissue.

It's exactly what it is.

It's an abnormal formation of fibrous tissue, mostly collagen, within the structural layers of the penis, specifically the tunica albigenia.

And the result isn't just a lump, right?

It actually changes the shape of the organ.

Oh, dramatically.

The text describes the physical manifestation as a curvature of the penis during erection.

And that's because that scar tissue, it doesn't stretch.

Precisely.

When the rest of the erectile tissue expands with blood, that fibrous patch, that plaque, it holds tight.

It acts like a tether.

So it bends.

It bends.

The penis curves toward the side of the lesion.

It can be physically painful and obviously can cause significant functional difficulty with intercourse.

It's not just a cosmetic quirk.

It's a real structural pathology.

That makes a lot of sense.

It's almost like putting a piece of tape on a balloon and then trying to blow it up.

That's a perfect analogy.

The tape side just won't expand with the rest of it.

Exactly.

Okay, let's shift gears to something potentially more sinister.

We're talking lesions and tumors.

The text starts with something benign, but visually, well, unpleasant,

condyloma acuminatum.

Yes.

The visual description in the notes is classic pathology language.

It describes these as warty cauliflower -like growths.

Cauliflower -like.

Why do pathologists always compare diseases to food?

It just ruins the grocery store for me.

It's a way to make the visual stick.

But yes, if you can imagine that textured bumpy surface of a cauliflower head, that's the lesion.

And what's driving this?

Is it just a random growth?

No, not at all.

It's viral.

The text specifically attributes this to HPV human papillomavirus, but here is the critical detail you have to memorize for any exam.

Okay.

It is HPV serotypes 6 and 11.

6 and 11.

Got it.

So 6 and 11 give you the cauliflower words.

I'm highlighting that because immediately after this, the text talks about squamous cell carcinoma actual cancer.

And that is also HPV, right?

It is.

But the numbers change.

And this distinction is, I mean, it's life or death.

Squamous cell carcinoma of the penis is pretty uncommon in the US.

But when it does happen, it is associated with high -risk HPV serotypes 16 and 18.

So 6 and 11 equals warts, which are benign.

16 and 18 equals cancer, which is malignant.

Exactly.

Do not mix those two pairs up.

The text also notes a demographic risk factor here, which is interesting.

What's that?

Squamous cell carcinoma is much more common in uncircumcised males.

And is that linked back to the same hygiene issue we talked about with inflammation?

That's the thinking, yes.

Chronic inflammation and the accumulation of irritants and carcinogens can be a setup for malignancy over a long timeline.

Okay.

Now before you get full -blown invasive cancer, there are warning signs.

The text lists these precursor lesions.

And the names, they sound like something from a fantasy novel.

We have Bowen disease, Bowenoid papulosis, and erythroplasia of Quirot.

They do sound quite exotic.

Let's break them down because the text gives them very specific identities.

First, Bowen disease.

This is essentially carcinoma in situ.

So cancer cells that are still contained, they haven't invaded the basement membrane yet, on the shaft of the penis.

Okay.

So pre -cancer on the shaft.

Exactly.

Second, Bowenoid papulosis.

This presents a little differently.

It's multiple reddish -brown papules.

And interestingly, the text notes that this is often seen in younger patients.

And unlike the others, specifically mentioned, it doesn't usually progress to invasive carcinoma.

So it kind of behaves a bit better.

And the third one, the Quirot one.

Erythroplasia of Quirot.

This is a very specific presentation.

It is described in the text as a red plaque.

And the key location is the gland's penis, the head.

So if a student sees the phrase red plaque on the glands in a question...

They should immediately, without hesitation,

think Erythroplasia of Quirot.

It's essentially the same histology as Bowen disease, but it gets a special name because of its specific location on the glands.

Got it.

Okay, let's wrap up this first section with functional disorders.

We have priapism.

Defined as a persistent painful erection.

And I really want to emphasize the word painful.

This is not a good time.

This is a medical emergency.

Why is it an emergency?

What's the danger?

Because if the blood stays trapped in the erectile tissue for too long, it deoxygenates.

You can get tissue ischemia, which is tissue death, and that can lead to pernative damage and erectile dysfunction.

The text lists the causes.

We have trauma, we have drugs, and specifically, Trazodone is called out.

Right.

Trazodone is an antidepressant that is pretty notorious for this particular side effect.

But the text also lists sickle cell anemia.

Can you explain that mechanism?

How does the shape of a blood cell cause this?

Yeah, it's all about blood flow, or lack thereof.

Sickle cells are rigid and sticky.

They're not smooth and flexible like normal red blood cells.

So the text describes a mechanism of blood sludging.

Sludging.

Essentially, the sickle cells get jammed in the small vascular channels of the penis.

They block the exit.

So arterial blood keeps pumping in, but the venous flood can't get out.

The traffic jam.

A very painful, very dangerous traffic jam.

And finally, on this list, erectile dysfunction, or ED,

the text gives a, I mean, it's a laundry list of causes.

It feels like almost anything can cause ED.

It really highlights how complex the physiology of an erection is.

It requires nerves, blood vessels, hormones, and psychology all working in perfect sync.

Right.

The text breaks down into buckets, which is helpful.

You have psychological factors, obviously.

Then hormonal, low testosterone, or even things like hypothyroidism, or prolactinoma, pituitary tumor.

Then there's vasculitis.

Right.

The text notes vascular insufficiency is the most common cause in men over age 50.

That makes sense.

If the arteries are getting clogged elsewhere in the body, like the heart, they're probably clogged in the penis too.

And neurologic causes?

Damage to the nerves.

The text lists multiple sclerosis, diabetic neuropathy, and interestingly, it also lists radical prostatectomy.

From cancer surgery.

Exactly.

If you remove the prostate for cancer, you often risk damaging the delicate cavernous nerves that run right alongside it and control erection.

And lastly, the medication list.

A big one.

Luperolide, methyl dopa, finasteride, and a lot of psychotropics.

The real takeaway for the learner is if a patient comes in complaining of ED, you have to look at their medication list first.

Okay.

That's the penis.

We've covered the delivery system.

Now let's travel upstream to the factory.

Part two, the testes.

The testes.

And this is a huge section we have a lot of ground to cover here.

Before we get to the really scary stuff, the tumors.

Let's talk about the non tumor pathology.

The text lists a bunch of words that end in cell A.

We've got varicocele, hydrocele, spermatol.

The apicelles.

Let's start with varicocele because there is a specific figure referenced here.

Figure 24 to 1.

Right.

So to understand this, you have to visualize the spermatic cord.

It's this bundle of structures and it's got arteries coming down and veins going up.

A varicocele is essentially a dilation of that network of veins called the Pampiniform venus plexus.

In plain English.

It's varicose veins of the scrotum.

The text has a very appetizing description for this.

A bag of worms.

A bag of worms.

You just can't unhear that.

It's gross, but it's incredibly accurate.

You palpate the scrotum.

It feels like a squishy tangled mass of tubes.

Just like a bag of worms.

And there's a side preference here, right?

It's not usually on both sides.

Yes.

This is a very high yield point.

The text explicitly states it is usually on the left side.

Does the text say why?

It doesn't go into the detail of anatomy of how the left gonadal vein drains into the left renal vein at a right angle.

But clinically, the rule is expect it on the left.

So if you see it on the right.

If you see a right -sided varicocele, especially one that appears suddenly, you should be suspicious of something else, something more sinister,

blocking the venous flow higher up.

And what's the major consequence of this bag of worms?

Infertility.

Why?

Is it just blocking the sperm from getting out?

No, it's all about temperature.

The reason the testes hang outside the body in the first place is to stay a few degrees cooler than core body temperature.

That's optimal for making sperm.

Right.

All that pooled warm venous blood in the bag of worms raises the local temperature.

A varicocele essentially cooks the sperm.

That is a powerful and unfortunate image.

Okay, so varicocele is veins.

What is a hydrocele?

Hydro refers to water.

So this is simply fluid accumulation within the tunic of aginalis.

That's the sac that surrounds the testes.

A spermatocel.

That is an epididymal cyst that specifically contains sperm.

It's a little pocket of fluid and sperm off the epididymis.

Now, how do you tell these apart from a solid tumor?

That seems pretty important.

Very.

The text gives a great physical exam tip, transillumination.

Shine a light through it.

Exactly.

You go into a dark room, you hold a flashlight or a pen light behind the scrotum, and a hydrocele or a spermatocel will light up like a lantern.

The light just passes right through the chlorofluid.

And a tumor won't.

A solid tumor or the testicle itself will block the light.

It's a fantastic low -tech way to answer the is it solid or liquid question.

Simple but effective.

Okay, let's move to inflammation.

Epididymitis and orchitis.

The text treats these a little differently.

Let's look at epididymitis first.

This is inflammation of the epididymis, the coiled tube on the back of the testicle where sperm mature.

The symptoms are fever and a gradual onset of scrotal pain.

But the high -yield goldmine here is the etiology.

The text splits the cause based on age.

The age split.

Walk us through this.

This feels important.

It is.

Visualize a line drawn at age 35.

Okay, 35.

If the man is under 35, the cause is almost always sexually transmitted.

Specifically, the text names N -Gunneria or C -trechomatis chlamydia.

And if he's over 35...

If the man is over 35, the cause changes completely.

It's usually urinary pathogens, bacteria from the gut, that have refluxed down the urinary tract.

Things like E.

coli or Pseudomonas.

That is such a clear dividing line.

Young guys, you think STIs.

Older guys, you think UTIs.

It's a generalization, of course, but for the purposes of the text and for any board exam, it's a hard and fast rule.

The text also throws in a little note that chronic epididymitis can be caused by TB.

Tuberculosis in the scrotum.

Yep.

TB can go anywhere.

It's a good reminder.

Now, compare that to orchitis.

Orchitis is inflammation of the testicle itself, not just the epididymis.

The symptoms here are often more acute, sudden pain and high fever.

And while bacteria can cause it, the text specifically highlights a viral cause.

Which is?

The mumps virus.

Mumps?

We don't see it much anymore, thanks to the MMR vaccine.

But historically, mumps orchitis is a major cause of infertility.

The virus just destroys the sperm -producing tubules.

Now we come to a true emergency.

Testicular torsion.

This is the nightmare scenario for an ER doc.

The text describes it as the twisting of the spermatic cord.

Imagine the testicle is hanging on its cord like a bell clapper.

If it twists, and it can do so spontaneously or after trauma,

it strangles the blood vessels inside that cord.

So no blood gets in or out?

Well, the thick -walled arteries might still pump some blood in for a little while, but the thin -walled veins are pinched shut immediately.

So the testicle engorges with blood it can't get rid of, and then the arterial supply cuts off completely.

And the text mentions painful hemorrhagic infarction.

That means the tissue dies because it's soaked in its own blood, but has zero oxygen.

And the end result mentioned is gangrene.

Gangrene.

So you lose the testicle.

If you don't get the patient to the operating room and surgically untwist it within about four to six hours, yes, you lose it.

It's an incredibly time -critical diagnosis.

One last structural issue before we dive into the big cancer section.

Cryptorchidism.

We touched on this briefly with the penis malformations.

Cryptorchidism is simply the failure of one or both tests to fully descend into the scrotum.

They get stuck upstairs.

They get stuck.

Usually somewhere along the path, often in the inguinal canal.

Does it really matter if we just leave them there?

I mean, functionally?

It matters immensely.

Yeah.

For two reasons.

One, the higher temperature inside the body means it won't produce sperm correctly.

But two, and this is the big one, the text is very clear.

Cryptorchidism carries a significantly increased risk for developing semenoma, a type of testicular cancer.

So that undescended testicle is a ticking time bomb for cancer.

It is.

And it's important to note, even if you surgically bring it down later in childhood, the risk of cancer in that testicle remains higher than normal for the rest of their life.

The tissue itself is just not normal from the start.

Briefly, the text outlines male infertility.

It seems to categorize it by where the break in the chain is, which is pretty logical.

Right.

It's a systems approach.

You can break it down into three main categories.

First, you have primary testicular dysfunction.

The factory itself is broken.

Maybe the lay -dig cells aren't making testosterone, or the seminiferous tubules are damaged.

Sperm count is low or zero.

Secondary hypogonadism.

The management is broken.

The pituitary or the hypothalamus isn't sending the right signals, LH and FSH, down to the testes to tell them what to do.

The factory is capable, but it's not getting any orders.

And the third type.

Exit issues.

The factory works, management is fine, but the delivery trucks are blocked.

So you have an obstruction of the vasodifrenes, or maybe disorder ejaculation.

It's a very logical way to troubleshoot the problem.

Okay.

Take a deep breath.

We are now entering part three.

Testicular cancer.

This is the heavyweight champion of this chapter.

A lot of detail here.

Let's start with the general principles.

If a learner takes nothing else away from this part, what is the classic presentation?

A firm, painless testicular mass.

I want to double -click on that word painless.

We just talk about torsion and epididymitis being incredibly painful.

Right.

And that's a key differentiator.

Pain usually points to infection, inflammation, or injury.

A painless hard lump is cancer until proven otherwise.

And who gets this?

Is there a demographic?

The text notes that Caucasians have a higher incidence than African Americans.

And as we already mentioned, cryptorchidism is a major risk factor.

The text says three to five times the normal risk.

It also lists testicular dysgenesis syndromes, like Clonfilter syndrome, as a risk factor.

Now, diagnosis.

This is fascinating to me.

The text implies there's a very strict rule about doing a biopsy.

It's the no -biopsy rule.

And it's one of the few places in oncology where this is true in almost every other cancer breast, lung, liver.

You stick a needle in it to get a piece of tissue to see what it is.

In testicular cancer, you do not do that.

Why not?

That seems completely counterintuitive.

It's all about anatomy and containment.

The scrotum has a completely different lymphatic drainage system than the testes do.

Okay.

If you stick a needle through the scrotal skin into the tumor,

you risk seeding the cancer cells along the needle tract.

You could plant them in the scrotal skin lymphatics.

You essentially spread the cancer into a whole new drainage basin just by trying to test it.

Wow.

So you've just made your problem much, much worse.

Infinitely worse.

Well, what do you do?

I'm guessing you just take the whole thing out.

You remove the whole thing.

It's called a radical inguinal orchiectomy.

Diagnosis and treatment happen at the same time.

You take it out, then you send it to pathology to look at it under the microscope.

Speaking of lymphatics, there is a clinical correlate here about metastasis that seems really important.

This is a favorite trick question on exams.

The testes hang in the scrotum, so you'd think cancer would spread to the groin lymph nodes, the inguinal nodes, right?

That would be the most logical assumption, yes.

But you have to remember embryology.

The testes started way up in the abdomen near the kidneys, and they descended during development.

They dragged their blood supply and their lymphatic vessels down with them.

Ah, so they still drain up.

They still drain up.

So testicular cancer spreads to the para -aortic lymph nodes.

Way deep in the belly.

Way up in the retroperitoneum.

By the aorta.

So a patient might present with a testicular mass and back pain from these swollen nodes, but have totally normal lymph nodes in his groin.

That is, anatomy is destiny in perfect action.

Okay, before we start classifying the actual tumors, the text lists serum tumor markers.

These seem like the check engine lights of testicular cancer.

They are absolutely crucial for diagnosis, for staging, and for monitoring a patient's response to treatment.

We have a diagnostic triad here.

A triad.

First, AFP, which is alpha -fetoprotein.

Second, beta -HCG.

And third, LDH, or lactate dehydrogenase.

Let's decode these.

Why would a man have beta -HCG?

That's the pregnancy hormone.

It is, and this is the key insight.

Some of these testicular tumors, specifically one called choreocarcinoma, are made of placental tissue.

They are germ cell tumors that have differentiated into placenta.

So they're making what the placenta makes.

They are pumping out pregnancy hormone.

So yes, a man with this type of testicular cancer can test positive on a home pregnancy test.

That is just wild.

Okay, what about AFP?

AFP is normally produced by the yolk sac in a developing fetus.

So if the tumor differentiates into yolk sac tissue, which it can, it starts pumping out AFP.

So HCG equals placenta tissue.

AFP equals yolk sac tissue.

You got it.

That's the key association.

And LDH.

What's that one for?

LDH is much less specific.

It's an enzyme that's found in pretty much all of our cells.

When there's a lot of rapid cell turnover, like in a fast growing,

tumor cells die, they break open, and LDH spills into the blood.

So it's a measure of bulk?

Exactly.

It's a measure of tumor burden.

It tells you how much cancer is there, not necessarily which specific type it is.

Okay.

Now we are ready to meet the tumors themselves.

The tax divides them into germ cell tumors and sex cord stromal tumors.

Let's focus on gene cell tumors first.

These seem to be the big ones.

They are.

Over 95 % of testicular cancers are germ cell tumors.

And the text splits these into seminoma and non -seminomatous.

It's a binary world.

Is it a seminoma?

Or is it something else?

This is the first most important distinction to make.

Let's start with seminoma.

The text says this is the most common type.

Most common in adults, with a mean age around 40.

And here is the good news.

It has an excellent prognosis.

Why is that?

It is exquisitely sensitive to both chemotherapy and radiation.

I mean, even if it has spread, you can often just melt it away with treatment.

The early stage cure rate is over 95%.

What does it look like, grossly?

The text describes it as a pale, tan, often bulging mass when you cut into it.

But microscopically, and the text referenced the figure 24 to 2 here, it is described as sheets of monotonous cells.

Monotonous, meaning they all look exactly the same.

Uniform, boring almost.

They have clear cytoplasm, round nuclei.

They're very orderly sheets and they're separated by thin fiberous septae.

The text also mentions you might see lymphocytes sprinkled in between the tumor cells, which is a characteristic feature.

Okay, so seminoma equals uniform, treatable, good outcome.

Now let's talk about the non -seminomatous tumors.

These seem to be the villains of the story.

They are generally more aggressive and they're a more varied group.

Let's run through them.

First on the list is embryonal carcinoma.

Okay.

This tends to affect younger men in their 20s and 30s and it's nasty.

Grossly, it's a bloody necrotic mess.

The text uses the words hemorrhage and necrosis.

Not a clean tan tumor like the seminoma.

Not at all and microscopically, instead of those monotonous sheets, you see large, primitive, ugly looking cells.

It's much more aggressive.

Next is chorio carcinoma.

We mentioned this one regarding the HCG marker.

Right, this is the placental tumor.

It is highly, highly malignant.

The scary feature here, which the text points out, is hematogenous spread.

It loves to jump into the blood vessels.

So it spreads through the blood, not the lymphatics.

Exactly and it does it very early.

So it spreads to the lungs and the liver very early in its course.

The text implies the primary tumor in the testicle might actually be quite small, right?

That's a key point.

You might have a tiny, pea -sized burned out scar of a tumor in the testicle, but the patient's lungs are already full of these cannonball metastases.

It's a terrifyingly aggressive cancer.

Next up, yolk sac tumor, also known as an endodermal sinus tumor.

The key context to remember here is pediatrics.

This is the most common germ cell tumor in children.

And the prognosis for kids.

Is it better?

In children, yes.

The prognosis is usually quite good.

The text mentions a specific histologic finding.

Schiller Duval bodies.

This is a pythognomonic buzzword you must know.

The text describes them as glomeruloid structures.

Under the microscope, they look like little kidney glomeruli.

If you see a Schiller Duval body, it is a yolk sac tumor, period.

End of story.

And finally, the most visually disturbing one of them all, teratoma.

Ah, yes.

Figure 24 -3.

The text describes a tumor producing visible hair and teeth.

It's the stuff of nightmares, really.

A teratoma is a tumor that's derived from all three embryonic germ layers, ectoderm, endoderm, and mesoderm.

It's trying to build a person, but it's doing it in a completely chaotic, disorganized way.

So you find all sorts of different tissues.

All sorts.

You find skin, hair, teeth, gut tissue, cartilage, bone, even thyroid tissue, all jumbled together in a single mass.

Now there is a crucial rule of age for teratomas in the testes.

This is absolutely vital to remember.

What is it?

In children, pre -puberty boys, teratomas are usually benign.

Okay.

In adults, teratomas are considered malignant.

That is a stark difference for the same tumor.

It is.

In an adult male, a teratoma has the potential to metastasize.

It's not just a surgical curiosity.

It's a cancer.

And the text notes that these different tumor types rarely play solo.

That's right.

Mixed germ cell tumors are actually very common.

The text says about 60 % of cases contain more than one component.

You might have embryonal carcinoma mixed with teratoma.

We call that a teratocarcinoma.

The prognosis in those cases depends on the worst component present.

Okay, that wraps up the germ cell tumors.

Let's quickly hit the sex cord stromal tumors.

This is the other major category.

We're talking about Laedig and Sertoli cells.

Exactly.

Let's start with Laedig cell tumors.

Remember from physiology, Laedig cells are the ones that make hormones.

So it makes sense that these tumors are often functional factories.

They produce androgens and estrogens.

So the symptoms are hormonal, not just a lump.

Exactly.

In an adult male, the excess estrogen can cause gynecomastia breast growth.

In a child, the excess androgen causes precocious puberty.

They hit puberty way, way too early.

And the prognosis.

The good news is, about 90 % of them are benign.

But they're fascinating because of that hormonal presentation.

Microscopically, the text notes that the cells have abundant pink cytoplasm, which is characteristic.

And Sertoli cell tumors.

The text is pretty brief on these.

They're rare, they're usually benign, and they tend to form tubules.

Not a major focus for exams.

Okay, two last other tumors to mention before we finally leave the testes.

First, testicular lymphoma.

This is a crucial demographic rule to remember.

If a man over the age of 60 comes in with a testicular mass, your first thought should not be semenoma.

It should be lymphoma.

So it's the most common testicular tumor in that age group.

It is.

Specifically, it's usually a type of non -Hodgkin lymphoma called diffuse large B -cell lymphoma.

So, young man, think germ cell tumor.

Old man, think lymphoma.

That's the rule of thumb.

And finally, a little history lesson.

Scrotal suimus cell carcinoma.

The text connects this to a specific occupational exposure.

And that is soot.

This was actually the first cancer ever linked to an environmental cause.

It was first described in chimney sweeps in 18th century London.

So the soot would get trapped.

It would get trapped in the rugae, the folds of the scrotal skin, leading to chronic inflammation, and eventually, squamous cell cancer.

That's a classic story in the history of oncology.

Incredible.

Okay.

We have survived the testes.

Take a deep breath.

Part six, pathology of the prostate.

The prostate.

A small organ that causes some very big problems.

The text divides the section into two behemoths.

BPH,

benign prostatic hyperplasia,

and adenocarcinoma cancer.

And once again, the text really emphasizes location, location, location.

Yes.

The prostate has different anatomical zones.

And different diseases live in different zones.

If you can understand that geography, you can understand the symptoms.

Let's start with BPH, benign prostatic hyperplasia.

First off, what is it physically?

What's happening?

It is a nodular hyperplasia.

So an increase in the number of cells.

And it's both the glandular tissue and the stromal tissue, the connective framework, that start growing.

Is it cancer?

Or is it pre -cancer?

Neither.

The text is very explicit about this.

It is not pre -malignant.

Having BPH does not mean you are going to get prostate cancer.

There are two separate disease processes that just happen to occur in the same organ.

What drives BPH?

Androgens.

Specifically, a very potent form of testosterone called DHT, or dihydrotestosterone.

An enzyme in the prostate called 5 -alpha reductase converts testosterone into DHT.

And DHT is what tells the prostate cells to grow.

And since men have testosterone their whole lives, this happens to almost everyone eventually.

It's an inevitability of aging, really.

The text says 70 % of men have it by age 60.

That number goes up to 90 % by age 80.

If you're a man and you live long enough, you will get BPH.

Now, the anatomy.

The location.

Where does this growth happen?

BPH occurs in the transition in central zones.

Okay, let's think of the prostate like a doughnut.

The urethra, the tube you pee through, is the hole in the middle.

Where are these zones?

These zones are the dough right next to the hole.

They are periretal.

So if that tissue grows?

It squeezes the hole shut.

The text describes a slit -like compression of the urethra.

And that explains all the symptoms.

Exactly.

The symptoms of BPH are obstructive,

hesitancy, meaning it's hard to start the stream,

dribbling at the end, a weak stream, a feeling of incomplete emptying, and retention.

The patient literally cannot push fluid through that squeeze tube.

And the complications follow that same logic.

Of course.

Urinary retention can lead to UTIs.

The bladder has to work much harder to push urine out, so the bladder muscle gets thick and stringy.

The text calls this trabeculation.

And if the pressure backs up all the way to the kidneys,

you get hydranaphyseus.

So how do we treat it?

The text lists three main ways.

Right.

First, there's surgery.

A TRP, transurethral resection of the prostate.

You basically go in with a scope and remount the channel to open the flow.

And medically.

Two main ways.

First, finasteride.

This is smart pharmacology.

It's a 5 -alpha reductase inhibitor.

It stops the conversion of testosterone into the more potent DHT.

No DHT.

The prostate shrinks.

And the third way?

Alpha -1 blockers like carizosin.

These don't shrink the prostate, but they relax the smooth muscle in the prostate and the bladder neck, which loosens the grip on the urethra and makes it easier to urinate.

OK, that's BPH.

The inner donut disease.

Now let's talk about prostate addenocarcinoma.

The cancer.

This is the most common cancer in U .S.

men.

And the text notes a significant demographic point.

The highest rate is in African Americans.

Where does this happen in the donut?

It arises in the posterior aspect of the peripheral zone.

The outer rind.

The part of the donut furthest from the hole.

Exactly.

And this single fact explains why prostate cancer is so often clinically silent in its early stages.

A tumor can grow quite large on the outer edge for years without ever squeezing the urethra.

So the patient has no trouble peeing.

That is terrifying.

If it's silent, how do we find it?

Well, because it's on the posterior surface, the backside of the prostate,

it is right up against the wall of the rectum.

So during a digital rectal exam, DRE, the doctor can feel it.

And what does it feel like?

The text describes it as an area of induration.

A hardness.

You feel this soft, spongy organ, and then suddenly there's a heart nodule.

A rock in the sponge.

So to summarize, BPH is central, so it causes obstruction.

Cancer is peripheral, so it's silent but palpable on an exam.

That is the golden rule of prostate pathology.

I know that distinction.

If we don't catch it on an exam or with screening, how does it eventually present?

Through metastasis.

And prostate cancer has a very specific and notorious target.

It loves to go to bone.

The text mentions that patients might present for the first time with lower back pain.

Because it's spread to the spine.

Yes.

Specifically, it causes osteoblastic metastasis to the lumbar spine.

Osteoblastic means it stimulates new bone formation.

So on an x -ray, you don't see holes being eaten in the bone.

You see bright white, dense spots of new bone.

Is there a lab value that goes with that?

There is.

Alkaline phosphatase.

It's an enzyme made by osteoblasts.

If that is elevated in a man with known prostate cancer, you have to assume it's in the bones.

What about the genetics?

The text mentions TMPRS S2 ETS fusion genes.

It says they're present in about 50 % of cases.

And the grading system.

We always hear about the Gleason score.

What is that actually measuring?

This is a nuanced but important point the text makes.

The Gleason system is based on glandular differentiation.

It's about architecture.

It's not looking at how ugly the individual cells are.

It's looking at the pattern they form.

Do they still form nice, round, separate glands?

That's a low grade.

Or are they just growing infused sheets with no glands at all?

That's a high grade.

And finally, what about PSA?

Prostate -specific antigen.

It's a useful tool, but it's imperfect.

It can be elevated in cancer, but it's also elevated in BPH and in prostatitis, which is just inflammation.

So it's not specific to cancer, but it's used for screening and more importantly for monitoring a patient's response to treatment.

We have one tiny section left, prostatitis.

Right, inflammation of the prostate.

What's the story here?

The text breaks it into two types.

Acute prostatitis.

This is usually from bacteria refluxing up the urethra.

The patient has a high fever and the prostate is exquisitely tender on exam.

And chronic.

Chronic prostatitis can be bacterial, but very often it's what the text calls chronic pelvic pain syndrome, which is non -bacterial.

We can't find a bug.

The patient just has this nagging painful urination and vague pelvic or low back pain.

Wow, we made it.

That was a marathon.

We covered the entire male reproductive tract.

From the tip of the glands all the way to the lumbar spine.

Let's do a lightning round to synthesize all of this.

I'll name the organ.

You give me the absolute don't miss concept from the text.

Just one sentence.

Okay, let's do it.

Ready.

Okay.

The penis.

HPV is the key player.

Low risk types 6 and 11 cause warts, while high risk types 16 and 18 drive you towards cancer.

The testes.

A painless mass is cancer until proven otherwise you never biopsy it and remember the rule of age for both infections and tumors.

And finally the prostate.

It's the donut.

BPH grows in the middle and squeezes the urethra causing obstruction.

That cancer grows on the outside edge making it silent but palpable.

An incredible summary.

It really drives it home.

It really all comes back to that theme we started with.

Anatomy is destiny.

If you can just visualize the structure the pathology makes perfect sense.

Well to all the learners out there.

Thank you so much for sticking with us through this very deep dive.

We really hope this chapter is now permanently etched into your brain.

Keep studying it pays off.

This is the last minute lecture team signing off.