Clinicians call it Benign Prostatic Hyperplasia (BPH). However, considering the terms “benign” and “hyperplastic”, it gets a little redundant (hyperplasia is a benign process). But to each his own, so pathologists call it Nodular Prostatic Hyperplasia (NPH) while clinicians persist with BPH. Maybe it’s to reassure themselves that it’s really benign.
Nodular prostatic hyperplasia is a disease of the prostate that has become nodular (gross) because of hyperplasia (microscopic).
The hallmark of NPH is nodularity.
Above is a gross picture of an enlarged prostate with NPH. It has been cut off from the midsection like breaking a pencil and seeing the lead inside. The pink circles are the nodules. Sometimes they grow inside a big nodule like an unfortunate fact that’s afflicted with acne that’s so wild that a zit grows on top of a zit.
These nodules are usually yellow-pink (some areas are yellow, some are pink) with a soft consistency. However, pathology students may be presented, with a specimen that’s been preserved longer than my grandpa so it may be very firm, almost hard like an overinflated basketball.
The blue circle is the prostatic urethra (remember urine? it forms in the kidney, goes down the ureter, stored in the bladder and released through the urethra). In the picture, the side with the pink circles and the other side of the urethra with no circles are the right and left lobes.
Normally the urethra is not squished into a thin line but because of the nodules, it accommodates the new houseguests however uncomfortable the urethra gets. The uninvited nodules’ overcrowding the urethra is the reason for the symptoms.
With a slit-like urethra, urine won’t be able to pass through freely. No free-flowing urine means it gets stuck in the bladder. Patients will feel the need to pee (urgency) but can’t pee or just dribble some. Sometimes they strain so hard they have some blood in the urine.
Same case, different prostate but this time on a microscopic level. Compare the gross picture that was cut in thick sections and now the microscopic pictures that are cut in super-thin sections. The pink circles are the nodules, which show tiny white to pink spaces that are crowded together (hyperplasia).
The blue circle is the urethra, this time not so much slit-like but you have to agree it’s deformed (normally it’s shaped like an “O” but here it looks like an outline of a rabbit’s head upside down).
Imagine this picture is inside one of those pink circles. I said earlier that there are white to pink spaces, those are the lumens of the prostate glands. It makes sense since the prostate is, after all, a gland so it would be made up of many glands performing the same function. And, being glands, they make something – or a secretion. That’s why some glands have a pink material (secretion) in the middle and some don’t.
The connective tissue between the glands in the stroma or mesenchyme. Yes, they’re all pink but remember the spaces are the lumens of glands and since a flower needs a supporting material to flourish like soil or water, the glands would need connective tissue or the stroma to support them as well.
In this case, the stroma is fibromuscular – for pathology students you can make it like it is made up of fibrous (fibrocytes) and muscular (myocytes) tissues or it is made up of Myofibrocytes, which are fibrocytes that have matured into muscle-like fibrocyte. Either way may be right.
The next picture is taken at higher power (20x). Spotty grammar aside, see the glands? They are tubuloalveolar glands. Imagine that they all converge into the urethra (the tubular part of the gland). That’s how their secretions get mixed in to form part of the semen.
The Prostate Gland
✅Hallmark is nodular prostatic enlargement.
✅Hyperplastic nodules are often multiple, mainly centered on proximal prostatic urethra involving submucosal compartment and TZ. #pathology #gross pic.twitter.com/LNfvdIZuj8
— Macroscopic Pathology (@Pathology3636) October 13, 2019
This picture is taken at high power (40x). These are a few glands that were part of the crowded group of glands inside the pink circle. The lining epithelium (of the gland!) is made up of two layers, the tall columnar mucus-secreting epithelium (neon green circles) and the myoepithelium (red circles).
Too much? The darker violet dots that seem to line the glands are the myoepithelium (the red circle on the lower part is the best representation). They form the base of the gland so they are also called basal cells.
Since they don’t secrete anything they don’t need that much cytoplasm that why you see more dots than pale pinks. The bigger but paler violet dots that are nearer the white space (or the lumen) are the nuclei (singular, nucleus) of the cells that actually secrete something (neon green circles).
In this case, they secrete mucin. The pale pink balloon “columns” that stretch out into the white space are the cytoplasm of the mucin-secreting cells (tall columnar mucin-secreting epithelium). If you still have questions hit the comment section (I don’t judge).
Having outlined the glands (including the lining epithelia) and the stroma, hyperplasia (increase in the number of cells) may mean an increase in the number of columnar mucus-secreting cells (glandular hyperplasia), the basal cells (basal cell hyperplasia) or the stroma (stromal hyperplasia. Or all three – it’s not rare.
The big, kinda round thing or nodule in the middle of the picture is an example of stromal hyperplasia. It is made up of pure stroma with no glands. The white jagged spaces inside the circle? They’re just holes as a result of histopath processing.
Remember this: Prostate glands are lined by basal cells which are myoepithelium and top of that are the tall columnar mucus-secreting cells. The glands are separated by stroma. In NPH the hyperplasia can be from the basal cells, the mucus-secreting cells, or the stroma, or all three. While you’re here read this awesome article on Male Sexuality facts.
Read also: Peyronies disease