• Clinical science

Benign prostatic hyperplasia

Summary

Benign prostatic hyperplasia (BPH) is a non-neoplastic glandular and stromal hyperplasia of the transition zone of the prostate. It is a common disorder affecting ∼ 40% of the male population by the age of 50 years. Although the etiology has not been conclusively established, sex hormones (androgens, estrogens, and androgen-estrogen imbalance) have been implicated as a key factor in the development of prostatic hyperplasia. Patients present with symptoms of bladder irritation (urinary frequency, urgency, urge incontinence), bladder outlet obstruction (urinary hesitancy, straining to urinate, sensation of incomplete voiding), and/or hematuria. Digital rectal examination reveals a smoothly enlarged, non-tender, and firm prostate. Diagnosis can be confirmed on abdominal ultrasound which demonstrates an enlarged prostate and increased post-void residual urine in the bladder. Bladder outlet obstruction can be quantitatively measured on uroflowmetry which shows a decreased maximal urinary flow rate. BPH is graded as mild, moderate and severe based on the frequency and severity of the symptoms. Behavioral modifications (e.g., night-time fluid restriction, urinating in a sitting position) are advised in all patients who are managed conservatively. Patients with mild/moderate BPH respond well to medical management with alpha-blockers (tamsulosin, doxazosin), 5-alpha-reductase inhibitors (finasteride), and parasympatholytics (oxybutynin). Severe BPH, unsuccessful medical therapy, and complications due to BPH are indications for surgery (e.g., transurethral resection of prostate, TURP). Complications of BPH include recurrent urinary tract infections (UTIs), urinary retention, bladder calculi, hydroureteronephrosis, and chronic kidney disease. BPH can recur after TURP in ∼ 15% of men. Prostate cancer can occur in patients with BPH, including in those who have undergone TURP. Normal prostate specific antigen (PSA) screening protocol is followed in these patients.

Definition

Epidemiology

Prevalence of BPH increases with age (present in ∼ 50% of men > 50 years and more than 80% of men > 80 years). [1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

The etiology is not fully understood. The following factors play a role in prostatic hyperplasia and growth:

BPH is not a risk factor for the development of prostate cancer.

Pathophysiology

Clinical features

  • Lower urinary tract symptoms (LUTS): the irritative and obstructive symptoms of BPH, grouped together [7]
    • Irritative symptoms of BPH
    • Obstructive symptoms of BPH
      • Hesitancy
      • Straining to urinate
      • Poor and/or intermittent stream (not continuous)
      • Prolonged terminal dribbling
      • Sensation of incomplete voiding
  • Often gross hematuria [8][9]
  • Digital rectal examination (DRE) findings: symmetrically enlarged, smooth (no nodules), firm, nontender prostate with rubbery or elastic texture
  • International prostate symptom score (IPSS): a scoring system based on the presence and severity of seven BPH symptoms in the past 30 days [10]
    • Based on the final scores, BPH is graded as follows:
      • 0–7 points: mild symptoms
      • 8–19 points: moderate symptoms
      • 20–35 points: severe symptoms
    • IPSS is also useful as a prognostic marker of disease progression and response to treatment.

To remember the symptoms of BPH, think “FUNWISE”: Frequency, Urgency, Nocturia, Weak stream /hesitancy, Intermittent stream, Straining to urinate, and Emptying (not emptying completely, terminal dribbling).

Diagnostics

Differential diagnoses

The differential diagnoses listed here are not exhaustive.

Treatment

Conservative management

Surgical intervention [22]

Since the peripheral zone (in which prostate cancer most commonly develops) is left intact in TURP, the risk of developing prostate cancer after TURP is the same as that in the general male population. Normal PSA screening protocol should be followed.

Almost all surgical interventions lead to retrograde ejaculation into the bladder because of anatomical changes.

Complications

We list the most important complications. The selection is not exhaustive.