Benign prostatic hyperplasia
- Lesion
With age, the inner prostate grows into nodules of glands and stroma that squeeze the urethra; it is hyperplasia, not cancer.
What it is
Benign prostatic hyperplasia (nodular hyperplasia) affects most men by their seventies. It arises in the transition zone and periurethral area, where androgen-driven growth factors make glands and fibromuscular stroma proliferate. Dihydrotestosterone (DHT), formed from testosterone by 5α-reductase type 2 in stromal cells, is the main driver; that is why 5α-reductase inhibitors shrink the gland. The nodules compress the prostatic urethra and cause outlet obstruction. BPH is not a precursor of carcinoma, which mostly arises in the peripheral zone.
Structure
- Enlarged gland with well-defined nodules that bulge on the cut surface; solid or with cysts containing milky fluid.
- Hyperplastic glands with papillary infoldings, lined by tall columnar luminal cells over a preserved basal layer; corpora amylacea in lumens.
- Stromal nodules of smooth muscle and fibroblasts; foci of infarction with squamous metaplasia at the edges.
BPH vs prostatic carcinoma
| Condition | Zone | Glands | Symptoms |
|---|---|---|---|
| Benign prostatic hyperplasia | Transition zone and periurethral | Nodules of glands with basal and luminal layers, plus stroma | Obstruction early |
| Prostatic carcinoma | Peripheral zone | Small infiltrative glands without basal cells | Often silent until advanced |
Clinical notes
- Lower urinary tract symptoms are common in older men; a digital rectal exam typically finds a smooth, enlarged, rubbery gland.
- Acute urinary retention can be triggered by infection, cold medications or alcohol.
Test yourself
Think of the answer, then tap the question to see it.
In which zone of the prostate does BPH arise?
The transition zone and periurethral glands.
Which hormone drives BPH and how is it formed?
Dihydrotestosterone, produced from testosterone by 5α-reductase type 2 in stromal cells.
Is BPH a precursor of prostate cancer?
No. Both are common in older men, but BPH is not a premalignant lesion.
Elsewhere in DurgiPedia
- Hyperplasia: physiologic and pathologic
- Epididymis, vas deferens, seminal glands and prostate
- Steroid hormone synthesis (overview)
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Benign Prostatic Hyperplasia (StatPearls (NCBI Bookshelf), 2024).
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Representative model, for educational purposes only.